Provided by: opendkim_2.11.0~beta2-7_amd64 bug


       opendkim.conf - Configuration file for opendkim




       opendkim(8) implements the DKIM specification for signing and verifying e-mail messages on
       a per-domain basis.  This file is its configuration file.

       Blank lines are ignored.  Lines containing a hash ("#") character  are  truncated  at  the
       hash character to allow for comments in the file.

       Other  content should be the name of a parameter, followed by white space, followed by the
       value of that parameter, each on a separate line.

       For parameters that are Boolean in nature, only the first byte of the value is  processed.
       For  positive  values,  the following are accepted: "T", "t", "Y", "y", "1".  For negative
       values, the following are accepted: "F", "f", "N", "n", "0".

       Many, but not all, of these parameters are also  available  as  command  line  options  to
       opendkim(8).   However,  new parameters are generally not added as command line options so
       the complete set of options is available here, and thus use of the configuration  file  is
       encouraged.   In  some future release, the set of available command line options is likely
       to get trimmed.

       See the opendkim(8) man page for  details  about  how  and  when  the  configuration  file
       contents are reloaded.

       Some  of  these  parameters are listed as having a type of "dataset".  See the opendkim(8)
       man page for a description of such parameters.

       Unless otherwise stated, Boolean values default to "false", integer values default  to  0,
       and string and dataset values default to being undefined.


       AllowSHA1Only (Boolean)
              Permit  verify  mode  when  only  SHA1 support is available.  RFC6376 requires that
              verifiers implement both SHA1 and SHA256 support.  Setting this feature changes the
              absence of SHA256 support from an error to a warning.

       AlwaysAddARHeader (Boolean)
              Add  an  "Authentication-Results:"  header  field  even  to  unsigned messages from
              domains with no "signs all" policy.  The reported DKIM result  will  be  "none"  in
              such  cases.   Normally  unsigned  mail  from non-strict domains does not cause the
              results header field to be added.

       AuthservID (string)
              Sets the "authserv-id" to use when generating  the  Authentication-Results:  header
              field  after  verifying  a  message.   The  default  is  to use the name of the MTA
              processing the message.  If the string "HOSTNAME" is provided, the name of the host
              running the filter (as returned by the gethostname(3) function) will be used.

       AuthservIDWithJobID (Boolean)
              If  "true",  requests  that  the  authserv-id  portion of the added Authentication-
              Results: header fields contain the job ID of the message being evaluated.

       AutoRestart (Boolean)
              Automatically re-start  on  failures.   Use  with  caution;  if  the  filter  fails
              instantly after it starts, this can cause a tight fork(2) loop.

       AutoRestartCount (integer)
              Sets the maximum automatic restart count.  After this number of automatic restarts,
              the filter will give up and terminate.  A value of 0 implies no limit; this is  the

       AutoRestartRate (string)
              Sets  the  maximum  automatic restart rate.  If the filter begins restarting faster
              than the rate defined here, it will give up and terminate.  This is a string of the
              form  n/t[u]  where  n  is  an  integer limiting the count of restarts in the given
              interval and t[u] defines the time interval through which the rate is calculated; t
              is an integer and u defines the units thus represented ("s" or "S" for seconds, the
              default; "m" or "M" for minutes; "h" or "H" for hours; "d" or "D" for  days).   For
              example,  a  value  of  "10/1h" limits the restarts to 10 in one hour.  There is no
              default, meaning restart rate is not limited.

       Background (Boolean)
              Causes opendkim to fork and exits immediately, leaving the service running  in  the
              background.  The default is "true".

       BaseDirectory (string)
              If  set,  instructs  the filter to change to the specified directory using chdir(2)
              before doing anything else.  This means  any  files  referenced  elsewhere  in  the
              configuration  file  can be specified relative to this directory.  It's also useful
              for arranging that any crash dumps will be saved to a specific location.

       BodyLengthDB (dataset)
              Requests that opendkim include a "l=" body length tag when the set contains any  of
              the  envelope  recipient addresses.  The addresses presented are tested against the
              database in various forms as described  under  the  SigningTable  setting  (below).
              This feature of the protocol exists to improve the likelihood that a signature will
              survive transit through a mailing list server, as they commonly append  footers  to
              messages.   Note,  however,  that  this  creates  a  potential security issue since
              someone could add arbitrary text to the signed  message  and  the  signature  would
              still validate.  See the DKIM specification for details.

       BogusKey (string)
              Instructs  the filter to treat a passing signature associated with a bogus (forged)
              key in a special way.  Possible values are neutral  (return  a  "neutral"  result),
              none  (take  no  special  action)  and  fail  (return  a "fail" result; this is the

       CaptureUnknownErrors (Boolean)
              When set, and on systems where MTA quarantine is available, the filter will request
              quarantine of a message that results in an internal error or resource exhaustion.

       Canonicalization (string)
              Selects  the  canonicalization  method(s)  to  be used when signing messages.  When
              verifying,   the   message's   DKIM-Signature:   header   field    specifies    the
              canonicalization  method.   The recognized values are relaxed and simple as defined
              by the DKIM specification.  The default is  simple.   The  value  may  include  two
              different canonicalizations separated by a slash ("/") character, in which case the
              first will be applied to the header and the second to the body.

       ChangeRootDirectory (string)
              Requests that the operating system change  the  effective  root  directory  of  the
              process to the one specified here prior to beginning execution.  chroot(2) requires
              superuser access. A warning will be generated if UserID is not also set.

       ClockDrift (integer)
              Sets the tolerance in seconds to be applied when determining  whether  a  signature
              was either expired or generated in the future.  The default is 300.

       Diagnostics (Boolean)
              Requests the inclusion of "z=" tags in signatures, which encode the original header
              field set  for  use  by  verifiers  when  diagnosing  verification  failures.   Not
              recommended for normal operation.

       DiagnosticDirectory (string)
              Directory into which to write diagnostic reports when message verification fails on
              a message bearing a "z=" tag.  If not  set  (the  default),  these  files  are  not

       DisableCryptoInit (Boolean)
              If  set,  skips  initialization  of the SSL library initialization steps, which are
              normally required in multi-threaded environments.  This assumes some other  library
              opendkim is using will do the required initialization and shutdown.

       DNSConnect (Boolean)
              Requests  that  the  asynchronous  resolver start using TCP immediately rather than
              using UDP until TCP is actually needed.  Does not work with all resolvers.

       DNSTimeout (integer)
              Sets the DNS timeout in seconds.  A value  of  0  causes  an  infinite  wait.   The
              default is 5.  Ignored if not using an asynchronous resolver package.  See also the
              NOTES section below.

       Domain (dataset)
              A set of domains whose mail should be signed  by  this  filter.   Mail  from  other
              domains will be verified rather than being signed.

              This  parameter is not required if a SigningTable is in use; in that case, the list
              of signed domains is implied by the lines in that file.

              This parameter is ignored if a KeyTable is defined.

       DomainKeysCompat (boolean)
              If set, backward compatibility with DomainKeys (RFC4870) key  records  is  enabled.
              When not set, such keys are considered to be syntactically invalid.

       DontSignMailTo (dataset)
              A  set of e-mail address, mail to which should never be signed by the filter.  Note
              that this is an "any" feature; if any one of the recipients of the message  matches
              a member of this list, the message will not be signed.

       EnableCoredumps (boolean)
              On  systems  that have such support, make an explicit request to the kernel to dump
              cores when the filter crashes for some reason.  Some modern UNIX  systems  suppress
              core  dumps  during  crashes for security reasons if the user ID has changed during
              the lifetime of the process.  Currently only supported on Linux.

       ExemptDomains (dataset)
              Specifies a set of domains, mail from which  should  be  ignored  entirely  by  the
              filter.   This is similar to the PeerList setting except that it bases its decision
              on the sender of the message as identified from the header fields or other  message
              data, not the identity of the SMTP client sending the message.

       ExternalIgnoreList (dataset)
              Identifies  a  set of "external" hosts that may send mail through the server as one
              of the signing domains without  credentials  as  such.   This  has  the  effect  of
              suppressing  the  "external  host  (hostname)  tried  to send mail as (domain)" log
              messages.  Entries in the data set should be of the  same  form  as  those  of  the
              PeerList option below.  The set is empty by default.

       FinalPolicyScript (string)
              Gives the name of a Lua script that should be run after the entire message has been
              received.  This can be used  to  enact  local  policy  decisions  such  as  message
              rejection,  quarantine,  rerouting,  etc. based on signatures found on the message,
              the results of attempts to verify them, and other  properties  of  the  message  or
              signatures.  See opendkim-lua(3) for details.

       FixCRLF (Boolean)
              Requests  that  the  DKIM  library  convert  bare  CRs and LFs to CRLFs during body
              canonicalization, anticipating that an MTA somewhere before delivery will  do  that
              conversion anyway.  The default is to leave them as-is.

       IdentityHeader (string)
              This specifies the header field where an identity is stored.  (Experimental feature
              not enabled for this installation.)

       IdentityHeaderRemove (Boolean)
              Remove the IdentityHeader after signing.  (Experimental  feature  not  enabled  for
              this installation.)

       IgnoreMalformedMail (boolean)
              Silently passes malformed messages without alteration.  This includes messages that
              fail the RequiredHeaders check, if enabled.  The default is to pass those  messages
              but add an Authentication-Results field indicating that they were malformed.

       Include (string)
              Names a file to be opened and read as an additional configuration file.  Nesting is
              allowed to a maximum of five levels.

       InternalHosts (dataset)
              Identifies a set internal hosts whose mail should be signed rather  than  verified.
              Entries  in  this  data  set  follow  the same form as those of the PeerList option
              below.  If not specified,  the  default  of  ""  is  applied.   Naturally,
              providing  a  value here overrides the default, so if mail from should be
              signed, the list provided here should include that address explicitly.

       KeepAuthResults (boolean)
              Suppresses removal of Authentication-Results header fields containing DKIM  results
              apparently  added  by  this  filter  (usually the result of a misconfiguration or a

       KeepTemporaryFiles (boolean)
              Instructs the filter to create temporary  files  containing  the  header  and  body
              canonicalizations  of  messages that are signed or verified.  The location of these
              files can be  set  using  the  TemporaryDirectory  parameter.   Intended  only  for
              debugging verification problems.

       KeyFile (string)
              Gives  the  location  of  a  PEM-formatted  private  key to be used for signing all
              messages.  Ignored if a KeyTable is defined.

       KeyTable (dataset)
              Gives the location of a file mapping  key  names  to  signing  keys.   If  present,
              overrides  any  KeyFile setting in the configuration file.  The data set named here
              maps each key name to three values: (a) the name  of  the  domain  to  use  in  the
              signature's "d=" value; (b) the name of the selector to use in the signature's "s="
              value; and (c) either a private key or a path to a file containing a  private  key.
              If  the  first  value consists solely of a percent sign ("%") character, it will be
              replaced by the apparent domain of the sender when generating a signature.  If  the
              third  value  starts  with  a  slash  ("/") character, or "./" or "../", then it is
              presumed to refer to a file from which the private key should be read, otherwise it
              is  itself  a PEM-encoded private key or a base64-encoded DER private key; a "%" in
              the third value in this case will be replaced by the apparent domain  name  of  the
              sender.   The SigningTable (see below) is used to select records from this table to
              be used to add signatures based on the message sender.

       LDAPAuthMechanism (string)
              Names the authentication mechanism to use when connecting to an LDAP  server.   The
              default is the empty string, meaning "simple" authentication should be done.

       LDAPAuthName (string)
              Specifies the authenticating name to use when using SASL to authenticate to an LDAP
              server.  Requires SASL support be installed on  the  local  system.   There  is  no

       LDAPAuthRealm (string)
              Specifies  the  authentication  realm  to use when using SASL to authenticate to an
              LDAP server.  Requires SASL support be installed on the local system.  There is  no

       LDAPAuthUser (string)
              Specifies the authenticating user to use when using SASL to authenticate to an LDAP
              server.  Requires SASL support be installed on  the  local  system.   There  is  no

       LDAPBindPassword (string)
              Specifies  the  password to use when conducting an LDAP "bind" operation.  There is
              no default.

       LDAPBindUser (string)
              Specifies the user ID to use when conducting an LDAP "bind" operation.  There is no

       LDAPDisableCache (Boolean)
              Suppresses creation of a local cache in front of LDAP queries.

       LDAPKeepaliveIdle (integer)
              Sets  the  number  of  seconds  a connection to an LDAP server needs to remain idle
              before TCP starts sending keepalive probes.  If not  specified,  the  LDAP  library
              default is used.

       LDAPKeepaliveInterval (integer)
              Sets  the  interval in seconds between TCP keepalive probes.  If not specified, the
              LDAP library default is used.

       LDAPKeepaliveProbes (integer)
              Sets the maximum number of keepalive probes TCP should send before  abandoning  the
              connection.  If not specified, the LDAP library default is used.

       LDAPTimeout (integer)
              Sets  the  time  in seconds after which an LDAP operation should be abandoned.  The
              default is 5.

       LDAPUseTLS (Boolean)
              Indicates whether or not a TLS connection should be established when contacting  an
              LDAP server.  The default is "False".

       LogResults (boolean)
              If  logging  is enabled (see Syslog below), requests that the results of evaluation
              of all signatures that were at least partly intact (i.e., the "d=", "s=", and  "b="
              tags could be extracted).

       LogWhy (boolean)
              If  logging  is  enabled (see Syslog below), issues very detailed logging about the
              logic behind the filter's decision to either sign a  message  or  verify  it.   The
              logic behind the decision is non-trivial and can be confusing to administrators not
              familiar with its operation.  A description of how the  decision  is  made  can  be
              found  in  the OPERATIONS section of the opendkim(8) man page.  This causes a large
              increase in the amount of log data generated for each  message,  so  it  should  be
              limited to debugging use and not enabled for general operation.

       MacroList (dataset)
              Defines  a  set  of MTA-provided macros that should be checked to see if the sender
              has been determined to be a local user and therefore whether  or  not  the  message
              should  be  signed.  If a value is specified matching a macro name in the data set,
              the value of the macro must match a value specified (matching  is  case-sensitive),
              otherwise the macro must be defined but may contain any value.  The set is empty by
              default, meaning macros are not considered when making  the  sign-verify  decision.
              The  general  format of the value is value1[|value2[|...]]; if one or more value is
              defined then the macro must be set to one of the listed values, otherwise the macro
              must be set but can contain any value.

              In  order  for  the macro and its value to be available to the filter for checking,
              the MTA must send it during the protocol exchange.  This is either accomplished via
              manual  configuration  of  the  MTA  to  send the desired macros or, for MTA/filter
              combinations that support the feature, the filter can request those macros that are
              of  interest.  The latter is a feature negotiated at the time the filter receives a
              connection from the MTA and its availability depends upon  the  version  of  milter
              used to compile the filter and the version of the MTA making the connection.

              This data set must be of type "file" or "csl".

       MaximumHeaders (integer)
              Defines  the  maximum  number  of  bytes  the header block of a message may consume
              before the filter will reject the  message.   This  mitigates  a  denial-of-service
              attack in which a client connects to the MTA and begins feeding an unbounded number
              of header fields of arbitrary size; since the filter keeps a cache  of  these,  the
              attacker  could  cause the filter to allocate an unspecified amount of memory.  The
              default is 65536; a value of 0 removes the limit.

       MaximumSignaturesToVerify (integer)
              Defines the maximum number of signatures on a message for which verification should
              be  conducted.   The default is three.  Signatures are selected from the top of the
              message downward.  If TrustSignaturesFrom is set, signatures from domains  in  that
              data  set  are  always  verified, which may consume part or all of, or even exceed,
              this limit.

       MaximumSignedBytes (integer)
              Specifies the maximum number of bytes of  message  body  to  be  signed.   Messages
              shorter  than  this  limit  will  be  signed in their entirety.  Setting this value
              implies use of BodyLengthDB for all addresses.

       MilterDebug (integer)
              Sets the debug level to be requested  from  the  milter  library.   Currently,  the
              highest meaningful value is 6.

       Minimum (string)
              Instructs  the verification code to fail messages for which a partial signature was
              received.  There are three possible formats: min indicating at least min  bytes  of
              the  message  must  be signed (or if the message is smaller than min then all of it
              must be signed); min% requiring that at least min percent of the  received  message
              must  be  signed;  and min+ meaning there may be no more than min bytes of unsigned
              data appended to the message for it to be considered valid.

       MinimumKeyBits (integer)
              Establishes a minimum key size for acceptable signatures.  Signatures with  smaller
              key  sizes, even if they otherwise pass DKIM validation, will me marked as invalid.
              The default is 1024.  A value of 0 accepts all keys.

       Mode (string)
              Selects operating modes.  The string is a concatenation of characters that indicate
              which  mode(s)  of  operation  are  desired.   Valid  modes  are  s  (signer) and v
              (verifier).  The default is sv except in test mode (see the opendkim(8)  man  page)
              in which case the default is v.  When signing mode is enabled, one of the following
              combinations must also be set: (a)  Domain,  KeyFile,  Selector,  no  KeyTable,  no
              SigningTable;  (b)  KeyTable, SigningTable, no Domain, no KeyFile, no Selector; (c)
              KeyTable, SetupPolicyScript, no Domain, no KeyFile, no Selector.

       MTA (dataset)
              A set of MTA names (a la the sendmail(8) DaemonPortOptions  Name  parameter)  whose
              mail should be signed by this filter.  There is no default, meaning MTA name is not
              considered when making the sign-verify decision.

       MTACommand (string)
              Specifies the path to an executable to be  used  for  sending  mail  such  as  that
              generated  by  SendReports.   The  default  is  /usr/sbin/sendmail.  The executable
              should accept typical sendmail(8) command line options "-t"  (take  addresses  from
              message  body)  and  "-f"  (set  envelope  sender),  accept  the new message on its
              standard input, and return a non-zero exit status on any error.

       MultipleSignatures (Boolean)
              Allow addition of multiple  signatures  when  a  signing  table  is  in  use.   See
              SigningTable for more information.

       MustBeSigned (dataset)
              Specifies  a  set  of  header  fields that, if present, must be covered by the DKIM
              signature when verifying a message.  If a header field in this set  is  present  in
              the  message  and  is  not  signed,  the  filter will treat even an otherwise valid
              signature as invalid.  The default is an empty list.

       Nameservers (string)
              Provides a comma-separated list of IP addresses that are to be used when doing  DNS
              queries to retrieve DKIM keys, VBR records, etc.  These override any local defaults
              built in to the resolver in use, which may be defined in /etc/resolv.conf or  hard-
              coded into the software.

       NoHeaderB (Boolean)
              If set, this feature suppresses the use of "header.b" tags in added Authentication-
              Results header fields.  The default is "false", which  means  those  tags  will  be

       OmitHeaders (dataset)
              Specifies a set of header fields that should be omitted when generating signatures.
              If an entry in the list names any  header  field  that  is  mandated  by  the  DKIM
              specification,  the entry is ignored.  A set of header fields is listed in the DKIM
              specification (RFC6376, Section 5.4) as "SHOULD NOT" be signed;  the  default  list
              for   this  parameter  contains  those  fields  (Return-Path,  Received,  Comments,
              Keywords, Bcc, Resent-Bcc and DKIM-Signature).  To omit no headers, simply use  the
              string  "."  (or  any  string that will match no header field names).  Specifying a
              list with this parameter replaces the default entirely, unless one entry is "*"  in
              which  case  the  list  is  interpreted  as  a  delta  to the default; for example,
              "*,+foobar" will use the entire default list plus the name "foobar", while "*,-Bcc"
              would use the entire default list except for the "Bcc" entry.

       On-BadSignature (string)
              Selects the action to be taken when a signature fails to validate.  Possible values
              (with abbreviated forms in parentheses): accept (a) accept the message; discard (d)
              discard  the  message; quarantine (q) quarantine the message; reject (r) reject the
              message; tempfail (t) temp-fail the message.  The default is accept.  Note that the
              "t"  (testing)  flag  in  a  DKIM key bypasses this behaviour; a bad signature that
              references a testing flag will still be delivered, though the added Authentication-
              Results  field  will  indicate  both  the  failed  result and the test mode so that
              consumers of the message can take appropriate action.

       On-Default (string)
              Selects the action to be taken when any verification or internal error of any  kind
              is  encountered.  This is processed before the other "On-" values so it can be used
              as a blanket setting followed by specific overrides.

       On-DNSError (string)
              Selects the action to be taken when a transient DNS error is encountered.  Possible
              values are the same as those for On-BadSignature.  The default is tempfail.

       On-InternalError (string)
              Selects  the action to be taken when an internal error of some kind is encountered.
              Possible values are  the  same  as  those  for  On-BadSignature.   The  default  is

       On-KeyNotFound (string)
              Selects  the  action  to  be  taken  when  the key referenced by a signature is not
              present in the DNS.  Possible values are the same  as  those  for  On-BadSignature.
              The default is accept.

       On-NoSignature (string)
              Selects  the  action  to be taken when a message arrives unsigned.  Possible values
              are the same as those for On-BadSignature.  The default is accept.

       On-Security (string)
              Selects the action to be taken when a message arrives  containing  properties  that
              may  be  a  security  concern.   Possible  values  are  the  same  as those for On-
              BadSignature.  The default is tempfail.

       On-SignatureError (string)
              Selects the action to be taken when a message cannot be signed  because  of  issues
              with  the message or the key provided for signing.  Possible values are the same as
              those for On-BadSignature.  The default is reject.

       OversignHeaders (dataset)
              Specifies a set of header fields that should be included in  all  signature  header
              lists  (the "h=" tag) once more than the number of times they were actually present
              in the signed message.  The set is empty by default.   The  purpose  of  this,  and
              especially  of  listing  an  absent  header  field,  is  to prevent the addition of
              important fields between the signer and the verifier.   Since  the  verifier  would
              include  that  header field when performing verification if it had been added by an
              intermediary, the signed message and the verified message were  different  and  the
              verification would fail.  Note that listing a field name here and not listing it in
              the SignHeaders list is likely to generate invalid signatures.

       PeerList (dataset)
              Identifies a set of "peers" that identifies clients  whose  connections  should  be
              accepted  without processing by this filter.  The set should contain on each line a
              hostname, domain name (e.g. ""), IP address, an IPv6 address (including
              an  IPv4 mapped address), or a CIDR-style IP specification (e.g. "").
              An entry beginning with a bang ("!") character means "not", allowing exclusions  of
              specific  hosts  that  are otherwise members of larger sets.  Host and domain names
              are matched first, then the IP or IPv6 address depending on  the  connection  type.
              More precise entries are preferred over less precise ones, i.e.  "" will
              match before "!".  The text form of IPv6 addresses will be forced  to
              lowercase  when queried (RFC5952), so the contents of this data set should also use
              lowercase.  The IP address portion  of  an  entry  may  optionally  contain  square
              brackets; both forms (with and without) will be checked.

       PidFile (string)
              Specifies the path to a file that should be created at process start containing the
              process ID.

       POPDBFile (dataset)
              Requests that the filter consult a set for IP addresses that should be allowed  for
              signing.  This  feature  was designed for POP-before-SMTP datastores.  (Not enabled
              for this installation.)

       Quarantine (Boolean)
              Requests  that  messages  which  fail  verification  be  quarantined  by  the  MTA.
              (Requires a sufficiently recent version of the milter library.)

       QueryCache (Boolean)
              Instructs  the  DKIM  library  to maintain its own local cache of keys and policies
              retrieved from DNS, rather than relying on  the  nameserver  for  caching  service.
              Useful if the nameserver being used by the filter is not local.

       RedirectFailuresTo (address)
              Messages  bearing  signatures that failed to verify are redirected to the specified
              address.  The original envelope recipient set is  recorded  in  the  header  before
              redirection occurs.  By default, no redirection is done.

       RemoveARAll (Boolean)
              Removes   all   Authentication-Results:   header   fields  that  also  satisfy  the
              requirements of RemoveARFrom below.  By  default,  only  those  containing  a  DKIM
              result are removed.

       RemoveARFrom (dataset)
              Defines  a  set  of hostnames whose Authentication-Results: header fields should be
              removed before the message is passed for delivery.  By default  only  those  header
              fields  matching the local host's canonical name will be removed.  Matching is only
              done  on  full  hostnames  (e.g.  "")  or  on  domain  names  (e.g.

       RemoveOldSignatures (Boolean)
              Removes all existing signatures when operating in signing mode.

       ReplaceHeaders (data set)
              Defines  a  set  of  header  fields that should be affected by the text replacement
              rules defined by the ReplaceRules setting.   By  default,  all  header  fields  are
              included.  (Note: Feature is experimental.)

       ReplaceRules (string)
              Specifies  a  file  containing a list of text replacement rules that are applied to
              the message header fields to replace certain content expected to be changed as  the
              message  passes  through  local  MTAs.   This  can  be used to accommodate expected
              changes such as those made to From: fields  by  MTA  "masquerade"  features.   Each
              entry  in the file consists of a POSIX regular expression, followed by a tab (ASCII
              9), followed by the text that should be used  to  replace  the  text  matching  the
              expression.   The  '#'  character  denotes the beginning of a comment and text from
              that point on in a single line is ignored.  Blank lines are also  skipped.   (Note:
              Feature is experimental.)

       ReportAddress (string)
              Specifies  the  string  to  use in the From: header field for outgoing reports (see
              SendReports below).  If not specified, the executing user and local  hostname  will
              be used to construct the address.

       ReportBccAddress (string)
              Specifies  address(es)  to  include in a Bcc: header field on outgoing reports (see
              SendReports below). If multiple  addresses  are  required,  they  should  be  comma

       RequestReports (boolean)
              When  signing,  includes  a  request  for  signature  evaluation  failures  in  the
              signature.  (See RFC6651 for details.)

       RequiredHeaders (boolean)
              Checks all messages for compliance with RFC5322 header  field  count  requirements.
              Non-compliant messages are rejected.

       RequireSafeKeys (boolean)
              When  reading  a key file, a message will be logged if the key file has the read or
              write bit set other than for the owner or for a group that the executing process is
              in.   With  this  feature  set  to "true", the filter will further consider this an
              error and refuse to make use of the file's contents.  The default is "true".

       ResignAll (boolean)
              Where ResignMailTo triggers a re-signing action, this flag indicates whether or not
              all  mail  should be signed (if set) versus only verified mail being signed (if not
              set).  (Experimental feature not enabled for this installation.)

       ResignMailTo (dataset)
              Checks each message recipient against the specified dataset for a matching  record.
              The  full  address  is  checked  in  each case, then the hostname, then each domain
              preceded by ".".  If there is a match, the value returned is  presumed  to  be  the
              name  of  a  key  in the KeyTable (if defined) to be used to re-sign the message in
              addition to verifying it.  If there is a match without a KeyTable, the default  key
              is applied.  (Experimental feature not enabled for this installation.)

       ResolverConfiguration (string)
              Provides  the given string as configuration information to the underlying resolver.
              For the standard UNIX resolver, this is unused; for Unbound, the string contains  a
              filename that is considered to be a configuration file.  There is no default.

       ResolverTracing (Boolean)
              Requests  resolver  tracing  features be enabled, if available.  The effect of this
              depends on how debugging features of the resolver might be implemented.   Currently
              only effective with the OpenDKIM asynchronous resolver library.

       ScreenPolicyScript (string)
              Gives  the  name  of a Lua script that should be run after all of the header fields
              have been processed for a message; in particular, this is  useful  after  all  DKIM
              signatures have been detected and initial evaluation has been done.  The script has
              access to all of the header fields and connection information and can  direct  that
              certain  signatures  be ignored based on that information.  See opendkim-lua(3) for

       SelectCanonicalizationHeader (string)
              Defines a header field name which, if present, adjusts which canonicalization  will
              be  used to generate an outgoing signature.  Overrides the Canonicalization setting
              if the header field is present.  The default is "X-Canonicalization".

       Selector (string)
              Defines the name of the selector to be used when signing messages.   See  the  DKIM
              specification  for  details.   Used  only  when  signing with a single key; see the
              SigningTable parameter below for more information.

              This parameter is ignored if a KeyTable is defined.

       SenderHeaders (dataset)
              Specifies an ordered list of header fields that should be searched to determine the
              sender  of a message.  The first header field found is the one whose value is used.
              This is mainly used when signing for deciding which signing request(s) to make.  By
              default,  the  "From"  header  field  is the only one checked.  See the OmitHeaders
              setting for a description of possible values.

       SenderMacro (string)
              Use the milter macro string to determine the sender of the message.  (Note: Feature
              is experimental.)

       SendReports (Boolean)
              If true, when a signature verification fails and the signature included a reporting
              request ("r=y") and  the  signing  domain  advertises  a  reporting  address  (i.e.
              ra=user) in a reporting record in the DNS, the filter will send a structured report
              to that address containing details needed to reproduce the  problem.   See  RFC6651
              for a complete description of this mechanism.

       SetupPolicyScript (string)
              Gives  the  name  of  a  Lua script that should be run once all header fields for a
              message have arrived.  The script has access  to  all  of  the  header  fields  and
              connection  information  and can request DKIM verification or signing based on that
              information.  See opendkim-lua(3) for details.

       SignatureAlgorithm (string)
              Selects the signing algorithm to use when generating signatures.  Use 'opendkim -V'
              to  see  the  list  of  supported  algorithms.   The default is rsa-sha256 if it is
              available, otherwise it will be rsa-sha1.

       SignatureTTL (integer)
              Sets the time-to-live, in seconds, of signatures generated by the filter.   If  not
              set, no expiration time is added to signatures.

       SignHeaders (dataset)
              Specifies  the  set  of  header  fields  that  should  be  included when generating
              signatures.  If the list omits any header  field  that  is  mandated  by  the  DKIM
              specification,  those fields are implicitly added.  By default, those fields listed
              in the DKIM specification as "SHOULD" be signed  (RFC6376,  Section  5.4)  will  be
              signed   by  the  filter.   See  the  OmitHeaders  configuration  option  for  more
              information about the format and interpretation of this field.

       SigningTable (dataset)
              Defines a table used to select one or more signatures to apply to a  message  based
              on  the address found in the From: header field.  Keys in this table vary depending
              on the type of table used; values in this data set should include  one  field  that
              contains  a name found in the KeyTable (see above) that identifies which key should
              be used in generating the signature, and an optional second field naming the signer
              of  the  message  that will be included in the "i=" tag in the generated signature.
              Note that the "i=" value will not be included in the signature if it conflicts with
              the signing domain (the "d=" value).

              If the first field contains only a "%" character, it will be replaced by the domain
              found in the From: header field.  Similarly, within the optional second field,  any
              "%" character will be replaced by the domain found in the From: header field.

              If  this  table  specifies  a regular expression file ("refile"), then the keys are
              wildcard patterns that are matched against the address found in  the  From:  header
              field.  Entries are checked in the order in which they appear in the file.

              For  all  other  database  types,  the full user@host is checked first, then simply
              host,  then  user@.domain  (with  all  superdomains   checked   in   sequence,   so
              ""     would     first     check     "",    then
              "", then ""), then .domain, then user@*, and finally *.

              In any case, only the first match is applied, unless MultipleSignatures is  enabled
              in which case all matches are applied.

       SMTPURI (string)
              Specifies  a  URI  (e.g., "smtp://localhost") to which mail should be sent via SMTP
              when notifications are generated.  (Not enabled for this installation.)

       Socket (string)
              Specifies  the  socket  that  should  be  established  by  the  filter  to  receive
              connections  from sendmail(8) in order to provide service.  socketspec is in one of
              two forms: local:path, which creates a UNIX domain socket at the specified path, or
              inet:port[@host]  or  inet6:port[@host] which creates a TCP socket on the specified
              port and in the specified protocol family.  If the host is not given  as  either  a
              hostname  or  an  IP  address,  the  socket will be listening on all interfaces.  A
              literal IP address must be enclosed in square brackets.  This option  is  mandatory
              either in the configuration file or on the command line.

       SoftStart (Boolean)
              If set, the inability to connect and authenticate to an LDAP or SQL server will not
              prevent the filter from starting, and reconnections  will  be  attempted  for  each
              query.  The default is "False".

       SoftwareHeader (Boolean)
              Causes  opendkim  to  add  an "DKIM-Filter" header field indicating the presence of
              this filter in the path of the message from injection to delivery.   The  product's
              name,  version,  and  the job ID are included in the header field's contents.  Note
              that the header field is not added if the Mode setting causes  the  message  to  be
              ignored  (e.g.,  if  only  signing mode is enabled and the configuration causes the
              message not to be signed, or only verify mode is enabled  and  configuration  would
              otherwise  have  caused the message to be signed, then it will not have this header
              field added).

       Statistics (filename)
              This specifies a file in which to store DKIM transaction statistics.  See opendkim-
              stats(8)  for  a mechanism to parse the file's contents, and opendkim-importstats()
              for a mechanism to translate the file's  contents  into  SQL  database  insertions.
              (Note: Feature is experimental.)

       StatisticsName (string)
              Defines  the name to be used as the reporting host in statistics logs.  By default,
              the local host's name returned  by  gethostname(3)  is  used.   (Note:  Feature  is

       StatisticsPolicyScript (string)
              The  statistics  script  is run after all of the DKIM verification and signing work
              has been completed but before any final message handling is done.  The main purpose
              of  this  script  is  to give the user an opportunity to examine the message or its
              signatures and make arbitrary additional statistical observations  that  should  be
              recorded by the statistics module.

       StatisticsPrefix (string)
              When  AnonymousStatistics  is  enabled,  this  string  may be specified and will be
              prepended to all data before hashing for more complete anonymization.   This  means
              two  records  from different sources referencing the same source will still produce
              different hashes, meaning such correlation is now only  possible  within  the  data
              from a single repoter.

       StrictHeaders (Boolean)
              If  set, instructs the DKIM library to refuse processing of a message if the header
              field count does not conform to RFC5322 Section 3.6.

       StrictTestMode (Boolean)
              Selects strict CRLF mode during testing (see  the  -t  command  line  flag  in  the
              opendkim(8)  man page); messages for which all header fields and body lines are not
              CRLF-terminated are considered malformed and will produce an error.

       SubDomains (Boolean)
              Sign subdomains of those listed by the Domain  parameter  as  well  as  the  actual

       Syslog (Boolean)
              Log via calls to syslog(3) any interesting activity.

       SyslogFacility (string)
              Log  via  calls  to syslog(3) using the named facility.  The facility names are the
              same as the ones allowed in syslog.conf(5).  The default is "mail".

       SyslogName (string)
              Log via calls to syslog(3) using that name. That way one could distinguish multiple
              instances.  The default is the name of the executable, normally "opendkim".

       SyslogSuccess (Boolean)
              Log  via  calls  to  syslog(3)  additional entries indicating successful signing or
              verification of messages.

       TemporaryDirectory (string)
              Specifies the  directory  in  which  temporary  canonicalization  files  should  be
              written.  The default is to use the libopendkim default location, currently /tmp.

       TestDNSData (data set)
              Provides  a  data  set whose keys will be treated as DNS record names and values as
              TXT record contents.  Intended for use during automated testing.

       TestPublicKeys (string)
              Names a file from which public keys should be read.  Intended for use  only  during
              automated testing.

       TrustAnchorFile (string)
              Specifies a file from which trust anchor data should be read when doing DNS queries
              and applying the DNSSEC protocol.  This is currently ignored unless the  underlying
              library  is compiled to use Unbound; see the documentation at at
              for the expected format of this file.

       TrustSignaturesFrom (dataset)
              This value consists of a set of domains that are considered trustworthy in terms of
              third-party  signatures.   That  is,  if  a message arrives with a signature from a
              domain that doesn't match the domain in the From: header, this  setting  determines
              whether  or  not  that  signature will be trusted.  If this value is undefined, all
              signatures are trusted.

       UMask (integer)
              Requests a specific permissions mask to be  used  for  file  creation.   This  only
              really  applies  to  creation  of  the  socket  when Socket specifies a UNIX domain
              socket, and to the PidFile (if any); temporary files are created by the  mkstemp(3)
              function  that  enforces a specific file mode on creation regardless of the process
              umask.  See umask(2) for more information.

       UnprotectedKey (string)
              Instructs the filter to treat a passing signature associated with a key found in an
              insecure  (i.e.  not  protected  by  DNSSEC) DNS record in a special way.  Possible
              values are neutral (return a "neutral" result), none (take no special action;  this
              is the default) and fail (return a "fail" result).

       UserID (string)
              Attempts  to  become the specified userid before starting operations.  The value is
              of the form userid[:group].  The process will be assigned all  of  the  groups  and
              primary group ID of the named userid unless an alternate group is specified.

       VBR-Certifiers (string)
              The  default  certifiers if not specified in X-VBR-Certifiers header field.  (Note:
              Feature is experimental.)

       VBR-PurgeFields (string)
              If set, arranges to remove X-VBR-Certifiers and X-VBR-Type fields on messages prior
              to sending them.  (Note: Feature is experimental.)

       VBR-TrustedCertifiers (string)
              A  colon or comma sparated list of trusted certifiers to accept when verifying VBR-
              Info header field.  (Note: Feature is experimental.)

       VBR-TrustedCertifiersOnly (Boolean)
              By default, the certifiers that are in both the trusted certifiers list (above) and
              those  in  the  message's VBR-Info header field will be checked for vouching.  With
              this option set, the trusted certifiers will be checked and the ones claimed by the
              message will be ignored.  (Note: Feature is experimental.)

       VBR-Type (string)
              This  default  VBR  type  if  not specified in the X-VBR-Type header field.  (Note:
              Feature is experimental.)

       WeakSyntaxChecks (Boolean)
              Requests that the library continue processing messages even if  syntax  errors  are
              discovered  early  in  message  analysis.   This  means, for example, that a signed
              message with a mangled From: field will still proceed to verification even  if  the
              author's domain could not be determined.


       When  using  DNS  timeouts (see the DNSTimeout option above), be sure not to use a timeout
       that is larger than the timeout being  used  for  interaction  between  sendmail  and  the
       filter.   Otherwise,  the  MTA  could  abort  a message while waiting for a reply from the
       filter, which in turn is still waiting for a DNS reply.

       Features that involve specification  of  IPv4  addresses  or  CIDR  blocks  will  use  the
       inet_addr(3)  function  to  parse that information.  Users should be familiar with the way
       that function handles the non-trivial cases (for example, "192.0.2/24" and  ""
       are not the same thing).


              Default location of this file.


       This man page covers version 2.11.0 of opendkim.


       Copyright (c) 2007, 2008, Sendmail, Inc. and its suppliers.  All rights reserved.

       Copyright (c) 2009-2015, The Trusted Domain Project.  All rights reserved.


       opendkim(8), opendkim-lua(3), sendmail(8)

       RFC5451 - Message Header Field for Indicating Message Authentication Status

       RFC5617 - DKIM Author Domain Signing Practises

       RFC5965 - An Extensible Format for Email Feedback Reports

       RFC6008  -  Authentication-Results  Registration  for  Differentiating among Cryptographic

       RFC6376 - DomainKeys Identified Mail

       RFC6651 - Extensions to DomainKeys Identified Mail (DKIM) for Failure Reporting

                                    The Trusted Domain Project                   opendkim.conf(5)