Ubuntu Manpage: clamav-milter.conf - Configuration file for clamav-milter

Provided by: clamav-milter_0.103.12+dfsg-0ubuntu0.22.04.1_amd64

NAME

       clamav-milter.conf - Configuration file for clamav-milter

DESCRIPTION

       clamav-milter.conf contains the configuration options for clamav-milter(8).

FILE FORMAT

       The  file  consists  of comments and options with arguments. Each line which starts with a
       hash (#) symbol is ignored by the parser. Options and arguments are case sensitive and  of
       the form Option Argument. The arguments are of the following types:

       BOOL   Boolean value (yes/no or true/false or 1/0).

       STRING String without blank characters.

       SIZE   Size  in  bytes.  You can use 'M' or 'm' modifiers for megabytes and 'K' or 'k' for
              kilobytes.

       NUMBER Unsigned integer.

MAIN OPTIONS

       Example
              If this option is set clamav-milter will not run.

       MilterSocket STRING
              Define the interface through which we communicate with  sendmail.  This  option  is
              mandatory!
              Possible formats are:
              [[unix|local]:]/path/to/file - to specify a unix domain socket
              inet:port@[hostname|ip-address] - to specify an ipv4 socket
              inet6:port@[hostname|ip-address] - to specify an ipv6 socket
              Default: unset

       MilterSocketGroup STRING
              Define the group ownership for the (unix) milter socket.
              Default: disabled (the primary group of the user running clamd)

       MilterSocketMode STRING
              Sets the permissions on the (unix) milter socket to the specified mode.
              Default: disabled (obey umask)

       FixStaleSocket BOOL
              Remove stale socket after unclean shutdown.
              Default: yes

       User STRING
              Run as another user (clamav-milter must be started by root for this option to work)
              Default: unset (don´t drop privileges)

       ReadTimeout NUMBER
              Waiting for data from clamd will timeout after this time (seconds).
              Default: 120

       Foreground BOOL
              Don´t fork into background.
              Default: no

       Chroot STRING
              Chroot  to  the  specified directory. Chrooting is performed just after reading the
              config file and before dropping privileges.
              Default: unset (don´t chroot)

       PidFile STRING
              Save the process identifier of a clamav-milter (main thread) to a specified file.
              Default: disabled

       TemporaryDirectory STRING
              Optional path to the global temporary directory.
              Default: system specific (usually /tmp or /var/tmp).

CLAMD OPTIONS

       ClamdSocket STRING
              Define the clamd socket to connect to  for  scanning.  This  option  is  mandatory!
              Syntax:
              ClamdSocket unix:path
              ClamdSocket tcp:host:port
              The first syntax specifies a local unix socket (needs an absolute path) e.g.:
              ClamdSocket unix:/var/run/clamd/clamd.socket
              The  second  syntax  specifies  a tcp local or remote tcp socket: the host can be a
              hostname or an ip address; the ":port" field is only required for  IPv6  addresses,
              otherwise it defaults to 3310 e.g.:
              ClamdSocket tcp:192.168.0.1
              This  option  can be repeated several times with different sockets or even with the
              same socket: clamd servers will be selected in a round-robin fashion.
              Default: no default

EXCLUSIONS

LocalNet STRING
Messages originating from these hosts/networks will not be scanned. This option
takes a host(name)/mask pair in CIRD notation and can be repeated several times. If
"/mask" is omitted, a host is assumed. To specify a locally originated, non-smtp,
email use the keyword "local"
Default: unset (scan everything regardless of the origin)

Whitelist STRING
This option specifies a file which contains a list of basic POSIX regular
expressions. Addresses (sent to or from - see below) matching these regexes will
not be scanned. Optionally each line can start with the string "From:" or "To:"
(note: no whitespace after the colon) indicating if it is, respectively, the
sender or recipient that is to be whitelisted. If the field is missing, "To:" is
assumed. Lines starting with #, : or ! are ignored.
Default: unset (no exclusion applied)

SkipAuthenticated STRING
Messages from authenticated SMTP users matching this extended POSIX regular
expression (egrep-like) will not be scanned. As an alternative, a file containing
a plain (not regex) list of names (one per line) can be specified using the prefix
"file:". e.g. SkipAuthenticated file:/etc/good_guys. Note: this is the AUTH login
name!
Default: unset (no whitelisting based on SMTP auth)

MaxFileSize SIZE
Messages larger than this value won´t be scanned. Make sure this value is lower or
equal than StreamMaxLength in clamd.conf
Default: 25M

ACTIONS

The following group of options controls the delivery process under different
circumstances. The following actions are available:
- Accept: The message is accepted for delivery
- Reject: Immediately refuse delivery (a 5xx error is returned to the peer)
- Defer: Return a temporary failure message (4xx) to the peer
- Blackhole (not available for OnFail): Like Accept but the message is sent to oblivion
- Quarantine (not available for OnFail): Like Accept but message is quarantined instead of
being delivered. NOTE: In Sendmail the quarantine queue can be examined via mailq -qQ. For
Postfix this causes the message to be placed on hold.

OnClean STRING
Action to be performed on clean messages (mostly useful for testing)
Default: Accept

OnInfected STRING
Action to be performed on infected messages
Default: Quarantine

OnFail STRING
Action to be performed on error conditions (this includes failure to allocate data
structures, no scanners available, network timeouts, unknown scanner replies and
the like)
Default: Defer

RejectMsg STRING
This option allows you to set a specific rejection reason for infected messages and
it´s therefore only useful together with "OnInfected Reject". The string "%v", if
present, will be replaced with the virus name.
Default: MTA specific

AddHeader STRING
If this option is set to "Replace" (or "Yes"), an "X-Virus-Scanned" and an "X-
Virus-Status" headers will be attached to each processed message, possibly
replacing existing headers. If it is set to Add, the X-Virus headers are added
possibly on top of the existing ones. Note that while "Replace" can potentially
break DKIM signatures, "Add" may confuse procmail and similar filters.
Default: no

ReportHostname STRING
When AddHeader is in use, this option allows you to set the reported hostname. This
may be desirable in order to avoid leaking internal names. If unset the real
machine name is used.
Default: disabled

VirusAction STRING
Execute a command (possibly searching PATH) when an infected message is found. The
following parameters are passed to the invoked program in this order: virus name,
queue id, sender, destination, subject, message id, message date. Note #1: this
requires MTA macroes to be available (see LogInfected below). Note #2: the process
is invoked in the context of clamav-milter. Note #3: clamav-milter will wait for
the process to exit. Be quick or fork to avoid unnecessary delays in email
delivery.
Default: disabled

LOGGING OPTIONS

LogFile STRING
Enable logging to selected file.
Default: no

LogFileUnlock BOOL
Disable a system lock that protects against running clamd with the same
configuration file multiple times.
Default: no

LogFileMaxSize SIZE
Limit the size of the log file. The logger will be automatically disabled if the
file is greater than SIZE. Value of 0 disables the limit.
Default: 1M

LogTime BOOL
Log time for each message.
Default: no

LogSyslog BOOL
Use system logger (can work together with LogFile).
Default: no

LogFacility STRING
Specify the type of syslog messages - please refer to 'man syslog' for facility
names.
Default: LOG_LOCAL6

LogVerbose BOOL
Enable verbose logging.
Default: no

LogInfected STRING
This option allows you to tune what is logged when a message is infected. Possible
values are Off (the default - nothing is logged), Basic (minimal info logged), Full
(verbose info logged)
Note: For this to work properly in sendmail, make sure the msg_id, mail_addr,
rcpt_addr and i macroes are available in eom. In other words add a line like:
Milter.macros.eom={msg_id}, {mail_addr}, {rcpt_addr}, i to your .cf file.
Alternatively use the macro: define(`confMILTER_MACROS_EOM', `{msg_id},
{mail_addr}, {rcpt_addr}, i')
Postfix should be working fine with the default settings.
Default: disabled

LogClean STRING
This option allows you to tune what is logged when no threat is found in a scanned
message.
See LogInfected for possible values and caveats.
Useful in debugging but drastically increases the log size.
Default: disabled

SupportMultipleRecipients BOOL
This option affects the behaviour of LogInfected, LogClean and VirusAction when a
message with multiple recipients is scanned:
If SupportMultipleRecipients is off (the default) then one single log entry is
generated for the message and, in case the message is determined to be malicious,
the command indicated by VirusAction is executed just once. In both cases only the
last recipient is reported.
If SupportMultipleRecipients is on then one line is logged for each recipient and
the command indicated by VirusAction is also executed once for each recipient.
Note: although it's probably a good idea to enable this option, the default value
is currently set to off for legacy reasons.
Default: no

NOTES

       All options expressing a size are limited to max 4GB. Values in excess will  be  reset  to
       the maximum.

FILES

       /etc/clamav/clamav-milter.conf

AUTHOR

       aCaB <acab@clamav.net>