Provided by: imapfilter_2.6.11-1build1_amd64 bug

NAME

       imapfilter_config — imapfilter configuration file

SYNOPSIS

       $HOME/.imapfilter/config.lua

DESCRIPTION

       imapfilter(1)  uses the Lua programming language as a configuration and extension language, therefore the
       configuration file is a Lua script.

       Although knowledge of Lua is not required to use imapfilter(1), it is nonetheless recommended, especially
       if one wants to extend it.  For more information on Lua see http://www.lua.org/docs.html.

CONVENTIONS

       A brief description of the Lua values and types mentioned hereafter in the manual page follows:

           The nil is the type of the value “nil”, whose main property is to be different from any other  value;
           usually it represents the absence of a useful value.

           The  boolean  is  the type of the values “true” and “false”.  Both “nil” and “false” make a condition
           false; any other value makes it true.

           The type number represents real numbers.

           The type string represents a sequence of characters and can be defined using  single  quotes,  double
           quotes or double square brackets.

           The  type  table  implements  associative  arrays,  that is, arrays that can be indexed not only with
           numbers, but with any value.

           A function is a first-class value; it can be  stored  in  variables,  passed  as  argument  to  other
           functions, and returned as a result.

OPTIONS

       Program's options are set using an already initialised table named “options”, in the following manner:

           options.timeout = 120
           options.namespace = false
           options.charset = 'ISO-8859-1'

       Available options are:

       cache   When  this  option  is  enabled,  parts  of  messages are cached locally in memory to avoid being
               downloaded more than once.  The cache is preserved for the current session  only.  This  variable
               takes a boolean as a value. Default is “true”.

       certificates
               When  this  option  is  enabled,  the  server certificate can be accepted and stored, in order to
               validate the authenticity of the server in future connections. This variable takes a boolean as a
               value. Default is “true”.

       charset
               Indicates to the server the character set  of  the  strings  for  the  searching  methods.   This
               variable  takes  a  string  as a value.  By default no character set is set, and thus plain ASCII
               should be assumed by the server.

       create  According to the IMAP specification, when trying to write a message to  a  non-existent  mailbox,
               the  server must send a hint to the client, whether it should create the mailbox and try again or
               not. However some IMAP servers don't follow the specification and don't send the correct response
               code to the client. By enabling this option the client tries to create the  mailbox,  despite  of
               the server's response. This variable takes a boolean as a value.  Default is “false”.

       close   This  option  controls  whether the currently selected mailbox is implicitly closed at the end of
               each performed operation, thus removing all messages that are marked deleted. This variable takes
               a boolean as a value.  Default is “false”.

       crammd5
               When this option is  enabled  and  the  server  supports  the  Challenge-Response  Authentication
               Mechanism  (specifically CRAM-MD5), this method will be used for user authentication instead of a
               plaintext password LOGIN.  This variable takes a boolean as a value.  Default is “true”.

       expunge
               Normally, messages are marked for deletion and are actually deleted when the mailbox  is  closed.
               When  this option is enabled, messages are expunged immediately after being marked deleted.  This
               variable takes a boolean as a value.  Default is “true”.

       info    When this options is enabled, a summary of the program's actions  is  printed,  while  processing
               mailboxes.  This variable takes a boolean as a value.  Default is “true”.

       keepalive
               The  time  in  minutes before terminating and re-issuing the IDLE command, in order to keep alive
               the connection, by resetting the inactivity timeout of the server.  A standards compliant  server
               must have an inactivity timeout of at least 30 minutes.  But it may happen that some IMAP servers
               don't  respect  that, or some intermediary network device has a shorter timeout.  By setting this
               option the above problem can be worked around. This variable takes a number as a  value.  Default
               is “29” minutes.

       limit   Some  servers have problems handling very long requests, but some of the requests that need to be
               sent can become quite long, because they apply an action for many messages at  once.   When  this
               option  is  set,  the client will try to break up these requests into smaller requests, that each
               operates on fewer messages at a time.  A good value for this would be “50”.  This variable  takes
               a number as a value.  Default is “0”.  See also the range option which is related.

       namespace
               When  enabled,  the  program  gets  the  namespace  of the user's personal mailboxes, and applies
               automatically the prefix and hierarchy delimiter to any mailboxes residing on  the  mail  server;
               the  user  must  use  the  ‘/’  character  as  the delimiter and “” (ie.  nothing) as the prefix,
               regardless of the folder format of the mail server.  This must be disabled, if the user wants  to
               manually  specify  mailbox  names (eg. because they are not part of the user's personal namespace
               mailboxes).  This variable takes a boolean as a value.  Default is “true”.

       persist
               When the recover option is enabled, the recovery function tries to restore the lost session,  but
               if  it fails to do so it gives up with an error.  In some cases a temporary network problem might
               cause the recovery function to fail, but the connection could be reestablished when trying a  bit
               later.  By enabling this option, the recovery function will be called repeatedly after a timeout,
               thus it will persist when trying to restore the session.  Note, that this will case the execution
               of  the  configuration  file  to be halted at the point of failure until the session is restored,
               which can have side effects to other established sessions, for example they might get dropped  by
               the server after a while.  This variable takes a boolean as a value.  Default is “false”.

       range   Some  servers have problems handling long sequence number ranges, and by setting this option, the
               number of messages included in each range can be limited.  A good value for this would  be  “50”.
               This  variable  takes  a  number  as a value.  By default no such limit is imposed.  See also the
               limit option which is related.

       recover
               With this option it is possible to control the recovery functionality, which restores  a  session
               (the  connection to the server and the IMAP state at the time), after some unexpected event takes
               place.  Currently there are two types of events that can end abnormally a  session,  and  finally
               cause the program to terminate: network errors, and the IMAP BYE response which a server can send
               anytime.   When  this  option is set to “all” the recovery function is triggered by both types of
               events, when set to “errors” only in the case of network errors,  and  when  set  to  “none”  the
               mechanism is completely disabled.  Default is “all”.

       reenter
               When  this option is enabled and the connection is recovered after some unexpected event while in
               IDLE mode (see also the recover option), the client will  re-enter  IDLE  mode.   But  when  this
               option  is  disabled,  and  after  the connection is recovered, the client will not re-enter IDLE
               mode, and instead will continue to execute the next line in the configuration file, ie.  the  one
               after enter_idle().  Default is “true”.

       starttls
               When this option is enabled and the server supports the IMAP STARTTLS extension, a TLS connection
               will  be  negotiated with the mail server in the beginning of the session.  This variable takes a
               boolean as value.  Default is “true”.

       subscribe
               By enabling this option new mailboxes that were automatically created, get also subscribed;  they
               are  set  active in order for IMAP clients to recognize them.  This variable takes a boolean as a
               value.  Default is “false”.

       timeout
               The time in seconds for the program to wait for a mail server's  response.   If  set  to  0,  the
               client  will  block  indefinitely.   This  variable  takes  a number as a value.  Default is “60”
               seconds.

       wakeonany
               By enabling this option the IDLE command will return on any  event  that  is  received  from  the
               server, and not just on the “RECENT” and “EXISTS” events, that normally indicate the arrival of a
               new message.  Examples of other events are “FETCH”, which indicates that the details of a message
               (eg.  its  flags)  have  been  modified,  or  “EXPUNGE”,  which indicates that a message has been
               deleted.  This variable takes a boolean as a value.  Default is “false”.

ACCOUNTS

       Accounts are initialized using the IMAP() function, and the details of the connection are  defined  using
       an account table:

           myaccount = IMAP {
               server = 'imap.mail.server',
               username = 'me',
               password = 'secret',
               ssl = 'auto'
           }

       An account table must have the following elements:

       server  The hostname of the IMAP server to connect to.  It takes a string as a value.

       username
               User's name.  It takes a string as a value.

       An account table can also have the following optional elements:

       password
               User's  secret  keyword.   If  a  password  wasn't  supplied  the user will be asked to enter one
               interactively the first time it will be needed (unless oauth2 has been set).  It takes  a  string
               as a value.

       oauth2  The  OAuth2  string  to  use  to  authenticate  if the server supports the XOAUTH2 authentication
               mechanism.  If the server does not support it and a password has been  also  set,  authentication
               will be attempted using the password.  It takes a string as a value.

               Note  that  this requires that an OAuth client ID and client secret have been obtained, an OAuth2
               token has been generated and authorized, a new access token has been generated using the  refresh
               token  if  the  last  access  token has expired, and an OAuth2 string has been generated from the
               access token.  The aforementioned OAuth2 string is a Base64 encoded string  that  should  be  set
               here.  For more information see https://developers.google.com/gmail/xoauth2_protocol.

       port    The  port  to connect to.  It takes a number as a value.  Default is “143” for imap and “993” for
               imaps.

       ssl     Forces an imaps connection and specifies the SSL/TLS protocol/version to be  used.   It  takes  a
               string as a value, specifically one of: “auto”, “tls1.2”, “tls1.1”, “tls1”, “ssl3”.

               Note  that  the  latest versions of the OpenSSL library have deprecated version specific methods,
               and the actual protocol version used will be  negotiated  to  be  the  highest  version  mutually
               supported by the client and the server.  This is also what the “auto” value does.

   LISTING
       The following methods can be used on an account to list mailboxes in a folder of an account:

       list_all(folder)
               Lists  all  the  available  mailboxes  in  the folder (string), and returns a table that contains
               strings, the available mailboxes, and a table that contains strings, the available folders.

       list_subscribed(folder)
               Lists all the subscribed mailboxes in the folder (string), and  returns  a  table  that  contains
               strings, the subscribed mailboxes, and a table that contains strings, the subscribed folders.

       The  following  methods  can  be used on an account to list mailboxes, using wildcards, in a folder of an
       account.  The ‘*’ wildcard, matches any character and the ‘%’ matches any  character  except  the  folder
       delimiter, ie.  non-recursively:

       list_all(folder, mailbox)
               Lists  all  the  available  mailboxes  in the folder (string) with the name mailbox (string), and
               returns a table that contains strings,  the  available  mailboxes,  and  a  table  that  contains
               strings, the available folders.  Wildcards may only be used in the mailbox argument.

       list_subscribed(folder, mailbox)
               Lists  all  the  subscribed  mailboxes in the folder (string) with the name mailbox (string), and
               returns a table that contains strings, the  subscribed  mailboxes,  and  a  table  that  contains
               strings, the subscribed folders.  Wildcards may only be used in the mailbox argument.

       Examples:

           mailboxes, folders = myaccount:list_subscribed('myfolder')
           mailboxes, folders = myaccount:list_all('myfolder/mysubfolder', '*')

   MANIPULATING
       The following methods can be used to manipulate mailboxes in an account:

       create_mailbox(name)
               Creates the name (string) mailbox.

       delete_mailbox(name)
               Deletes the name (string) mailbox.

       rename_mailbox(oldname, newname)
               Renames the oldname (string) mailbox to newname (string).

       subscribe_mailbox(name)
               Subscribes the name (string) mailbox.

       unsubscribe_mailbox(name)
               Unsubscribes the name (string) mailbox.

       Examples:

           myaccount:create_mailbox('mymailbox')
           myaccount:subscribe_mailbox('mymailbox')
           myaccount:unsubscribe_mailbox('myfolder/mymailbox')
           myaccount:delete_mailbox('myfolder/mymailbox')

MAILBOXES

       After  an IMAP account has been initialized, mailboxes residing in that account can be accessed simply as
       elements of the account table:

           myaccount.mymailbox

       If mailbox names don't only  include  letters,  digits  and  underscores,  or  begin  with  a  digit,  an
       alternative form must be used:

           myaccount['mymailbox']

       A mailbox inside a folder can be only accessed by using the alternative form:

           myaccount['myfolder/mymailbox']

       The  methods that are available for an account (eg.  list_all(), create_mailbox(), etc.) , are considered
       keywords and must not be used as mailbox names, and the same also applies for any string starting with an
       underscore, as they are considered reserved.

   CHECKING
       The following methods can be used to check the status of a mailbox:

       check_status()

               The check_status() method gets the current status of a mailbox, and returns four values of number
               type: the total number of messages, the number of recent messages, the number of unseen  messages
               in the mailbox, and the next UID to be assigned to a new message in the mailbox.

       enter_idle()
               The  enter_idle()  method implements the IMAP IDLE (RFC 2177) extension.  By using this extension
               it's not necessary to poll the server for  changes  to  the  selected  mailbox  (ie.   using  the
               check_status()  method),  but  instead  the  server sends an update when there is a change in the
               mailbox (eg. in case of new mail).  When the enter_idle() method has been called no more commands
               in the configuration file  are  executed  until  an  update  is  received,  at  which  point  the
               enter_idle()  method  returns.   For  the  enter_idle()  to  work,  the  IDLE extension has to be
               supported by the IMAP server.

               The enter_idle() method returns a value  of  type  boolean:  “true”  if  the  IDLE  extension  is
               supported  and  there  was  a  update  in  the  mailbox, and “false” if the IDLE extension is not
               supported, in which case the method returns immediately.  When the  aforementioned  return  value
               was  “true”,  an  additional  second  value of type string is also returned, indicating the event
               received from the server, which is useful when the wakeonany option has been enabled.

               Apart from an event received by the server, the SIGUSR1 or SIGUSR2 signals can also interrupt the
               IDLE mode at any time, and the execution of the configuration file will then  continue  from  the
               next line after the enter_idle().  In this case only the value “true” is returned.

       Examples:

           exist, unread, unseen, uidnext = myaccount.mymailbox:check_status()
           update = myaccount.mymailbox:enter_idle()
           update, event = myaccount.mymailbox:enter_idle()

   SEARCHING
       The  searching  methods  in this subsection can be applied to any mailbox.  They return a special form of
       table, that contains the messages that match the searching method.  This table can be combined with other
       tables using logic theory. There are three available operations, that  implement  logical  “or”,  logical
       “and” and logical “not”.

       The logical “or” is implemented using the ‘+’ operator:

           results = myaccount.mymailbox:is_unseen() +
                     myaccount.mymailbox:is_larger(100000)

       The logical “and” is implemented using the ‘*’ operator:

           results = myaccount.mymailbox:is_unseen() *
                     myaccount.mymailbox:is_larger(100000)

       The logical “not” is implemented using the ‘-’ operator:

           results = myaccount.mymailbox:is_unseen() -
                     myaccount.mymailbox:is_larger(100000)

       The  three  logical  operators  can  be  combined  in  the  same expression. The logical “and” has higher
       precedence than the logical “or” and the logical “not”, with the latter two having the  same  precedence,
       and parentheses may be used to change this behaviour:

           results = myaccount.mymailbox:is_unseen() +
                     myaccount.mymailbox:is_larger(100000) *
                     myaccount.mymailbox:contain_subject('test')

           results = ( myaccount.mymailbox:is_unseen() +
                       myaccount.mymailbox:is_larger(100000) ) *
                       myaccount.mymailbox:contain_subject('test')

       The returned tables of the searching methods can also be stored in variables and then further processed:

           unseen = myaccount.myaccount:is_unseen()
           larger = myaccount.mymailbox:is_larger(100000)
           subject = myaccount.mymailbox:contain_subject('test')
           results = unseen + larger * subject

       A composite filter that includes one or more simple rules can be defined:

           myfilter = function ()
                          return myaccount.mymailbox:is_unseen() +
                                 myaccount.mymailbox:is_larger(100000) *
                                 myaccount.mymailbox:contain_subject('test')
                      end

           results = myfilter()

       Composite filters can may be more dynamic by adding arguments:

           myfilter = function (mailbox, size, subject)
                          return mailbox:is_unseen() +
                                 mailbox:is_larger(size) *
                                 mailbox:contain_subject(subject)
                      end

           results = myfilter(myaccount.mailbox, 100000, 'test')

       It  is  also  possible  to  combine  the  searching methods in different mailboxes, either at the same or
       different accounts, for example when the same actions will be executed on messages residing in  different
       mailboxes or accounts.

           results = myaccount.mymailbox:is_unseen() +
                     myaccount.myothermailbox:is_larger(100000) +
                     myotheraccount.myothermailbox:contain_subject('test')

       The following method can be used to get all messages in a mailbox:

       select_all()
               All messages.

       The following methods can be used to search for messages that are in a specific state:

       is_answered()
               Messages that have been answered.

       is_deleted()
               Messages that are marked for later removal.

       is_draft()
               Messages that have not completed composition.

       is_flagged()
               Messages that are flagged for urgent/special attention.

       is_new()
               Messages  that  are recently arrived (this session is the first to have been notified about these
               messages) and have not been read.

       is_old()
               Messages that are not recently arrived (this session is not the first to have been notified about
               these messages) and have not been read.

       is_recent()
               Messages that are recently arrived (this session is the first to have been notified  about  these
               messages).

       is_seen()
               Messages that have been read.

       is_unanswered()
               Messages that have not been answered.

       is_undeleted()
               Messages that are not marked for later removal.

       is_undraft()
               Messages that have completed composition.

       is_unflagged()
               Messages that are not flagged for urgent/special attention.

       is_unseen()
               Messages that have not been read.

       The following method can be used to search for messages that have a specific keyword flag set:

       has_keyword(flag)
               Messages with the specified keyword flag (string) set.
       has_unkeyword(flag)
               Messages without the specified keyword flag (string) set.

       The following methods can be used to search for messages based on their size:

       is_larger(size)
               Messages that are larger than the size (number) in octets (bytes).

       is_smaller(size)
               Messages that are smaller than the size (number) in octets (bytes).

       The following methods can be used to search for messages based on their age:

       is_newer(age)
               Messages that are newer than the age (number) in days.

       is_older(age)
               Messages that are older than the age (number) in days.

       The  following  methods  can  be  used to search for messages based on their arrival or sent date, in the
       “day-month-year” form, where day is the day of the month as  a  decimal  number  (01-31),  month  is  the
       abbreviated  month  ( “Jan”, “Feb”, “Mar”, “Apr”, “May”, “Jun”, “Jul”, “Aug”, “Sep”, “Oct”, “Nov”, “Dec”)
       and year is the year as decimal number including the century (eg. 2007):

       arrived_before(date)
               messages that have arrived earlier than the date (string), where date is in the  “day-month-year”
               form.

       arrived_on(date)
               Messages that have arrived within the date (string), where date is in the “day-month-year” form.

       arrived_since(date)
               Messages  that  have  arrived  within  or  later  than  the  date  (string), where date is in the
               “day-month-year” form.

       sent_before(date)
               Messages  that  have  been  sent  earlier  than  the  date  (string),  where  date  is   in   the
               “day-month-year” form.

       sent_on(date)
               Messages  that  have  been  sent  within the date (string), where date is in the “day-month-year”
               form.

       sent_since(date)
               Messages that have been sent within or later than  the  date  (string),  where  date  is  in  the
               “day-month-year” form.

       The  following methods can be used to do case-insensitive searching, for messages that contain a specific
       word or phrase:

       contain_bcc(string)
               Messages that contain the string (string) in the “Bcc” header field.

       contain_cc(string)
               Messages that contain the string (string) in the “Cc” header field.

       contain_from(string)
               Messages that contain the string (string) in the “From” header field.

       contain_subject(string)
               Messages that contain the string (string) in the “Subject” header field.

       contain_to(string)
               Messages that contain the string (string) in the “To” header field.

       contain_field(field, string)
               Messages that contain the string (string) in the field (string) header field.

       contain_body(string)
               Messages that contain the string (string) in the message body.

       contain_message(string)
               Messages that contain the string (string) in the message.

       The following methods can be used to do case-sensitive searching, for  messages  that  match  a  specific
       regular  expression  pattern.  The  matching mechanism that is used to support this is based on the Perl-
       compatible regular expressions (PCRE), and more information about the patterns and modifiers that can  be
       used, is available in the relevant documentation at http://pcre.org/original/doc/html/.

       This  way  of  searching is not supported by the IMAP protocol, and this means that what actually happens
       under the hood, is that the relevant parts of all the messages are downloaded and matched locally.  It is
       therefore recommended to use these methods with meta-searching  (see  following  section),  in  order  to
       narrow down the set of messages that should be searched, and thus minimize what will be downloaded.

       Note  that  due  to  Lua  using  backslash  ‘\’ as an escape character for its strings, one has to double
       backslashes in order to insert a single backslash inside a regular expression pattern:

       match_bcc(pattern)
               Messages that match the regular expression pattern (string) in the “Bcc” header field.

       match_cc(pattern)
               Messages that match the regular expression pattern (string) in the “Cc” header field.

       match_from(pattern)
               Messages that match the regular expression pattern (string) in the “From” header field.

       match_subject(pattern)
               Messages that match the regular expression pattern (string) in the “Subject” header field.

       match_to(pattern)
               Messages that match the regular expression pattern (string) in the “To” header field.

       match_field(field, pattern)
               Messages that match the regular expression pattern (string) in the field (string) header field.

       match_header(pattern)
               Messages that match the regular expression pattern (string) in the message header.

       match_body(pattern)
               Messages that match the regular expression pattern (string) in the message body.

       match_message(pattern)
               Messages that match the regular expression pattern (string) in the message.

       The following method can  be  used  to  search  for  messages  using  user  queries  based  on  the  IMAP
       specification (RFC 3501 Section 6.4.4):

       send_query(criteria)
               Searches messages by sending an IMAP search query as described in the search criteria (string).

       Examples:

           results = myaccount.mymailbox:select_all()
           results = myaccount.mymailbox:is_new()
           results = myaccount.mymailbox:is_recent()
           results = myaccount.mymailbox:is_larger(100000)
           results = myaccount.mymailbox:is_older(10)
           results = myaccount.mymailbox:has_keyword('MyFlag')
           results = myaccount.mymailbox:arrived_before('01-Jan-2007')
           results = myaccount.mymailbox:sent_since('01-Jan-2007')
           results = myaccount.mymailbox:contain_subject('test')
           results = myaccount.mymailbox:contain_field('Sender', 'user@host')
           results = myaccount.mymailbox:contain_body('hello world')
           results = myaccount.mymailbox:match_from('.*(user1|user2)@host')
           results = myaccount.mymailbox:send_query('ALL')

           results = myaccount['mymailbox']:is_new()
           results = myaccount['myfolder/mymailbox']:is_recent()

RESULTS

       After  one  of more searching methods have been applied to one or more mailboxes, the result contains all
       the necessary information, such as which messages matched in which mailboxes.  Using  this  result  these
       messages can be either searched further or processed in various way.

   META-SEARCHING
       The  results  of the searching methods can be searched further on in the same way as searching is done in
       mailboxes.  The difference is that instead of doing the search in the  whole  mailbox,  ie.  in  all  the
       messages, it is instead done only to those messages that were returned in a previous search.

       Examples:

           results:match_message('^[Hh]ello world!?$')
           myaccount.mymailbox:is_new():match_body('^[Ww]orld, hello!?$')

   PROCESSING
       The processing methods are applied to the results that searching returned.

       The following method can be used to delete messages in a mailbox:

       delete_messages()
               Deletes the messages that matched.

       The  following  methods  can  be  used  to  copy  and move messages in a mailbox at the same or different
       accounts.  If the destination mailbox is in a  different  account  than  the  source  mailbox,  then  the
       messages are downloaded and then uploaded to the destination:

       copy_messages(destination)
               Copies the messages to the destination, which is a mailbox at an account.

       move_messages(destination)
               Moves the messages to the destination, which is a mailbox at an account.

       The following methods can be used to mark messages in a mailbox:

       mark_answered()
               Marks the messages as answered.

       mark_deleted()
               Marks the messages for later removal.

       mark_draft()
               Marks the messages as draft.

       mark_flagged()
               Marks the messages for urgent/special attention.

       mark_seen()
               Marks the messages as read.

       unmark_answered()
               Unmarks the messages that have been marked as answered.

       unmark_deleted()
               Unmarks the messages that have been marked for later removal.

       unmark_draft()
               Unmarks the messages that have been marked as draft.

       unmark_flagged()
               Unmarks the messages that have been marked for urgent/special attention.

       unmark_seen()
               Unmarks the messages that have been marked as read.

       The  following  methods  can  be  used  to  flag  messages  in  a  mailbox. The standard system flags are
       “\Answered”, “\Deleted”, “\Draft”, “\Flagged”, “\Seen”,  while  if  the  server  supports  it,  new  user
       keywords may be defined:

       add_flags(flags)
               Adds the flags (table that contains strings) to the messages.

       remove_flags(flags)
               Removes the flags (table that contains strings) from the messages.

       replace_flags(flags)
               Replaces the flags (table that contains strings) of the messages.

       Examples:

           results:delete_messages()
           results:copy_messages(myaccount.myothermailbox)
           results:move_messages(myotheraccount.mymailbox)
           results:mark_seen()
           results:unmark_flagged()
           results:add_flags({ 'MyFlag', '\\Seen' })
           results:remove_flags({ '\\Seen' })

           results:move_messages(myotheraccount['myfolder/mymailbox'])

MESSAGES

       The messages that are residing in any mailbox can be also accessed, as a whole or in parts.  Messages can
       be accessed using their unique identifier (UID):

           myaccount.mymailbox[22]

       The UIDs of messages the user is interested in, are gained from the results of searching:

           results = account.INBOX:is_unseen()
           for _, message in ipairs(results) do
               mailbox, uid = table.unpack(message)
               header = mailbox[uid]:fetch_header()
           end

   FETCHING
       The  following  methods  can  be  used  to  fetch  parts  of messages.  The methods return a string.  The
       downloaded message parts are cached locally, so they can be reused inside the same program session:

       fetch_message()
               Fetches the header and body of the message.

       fetch_header()
               Fetches the header of the message.

       fetch_body()
               Fetches the body of the messages.

       fetch_field(field)
               Fetches the specified header field (string) of the message.

       fetch_part(part)
               Fetches the specified part (string) of the message.

       The following methods can be used to fetch details about the state of a message:

       fetch_flags()
               Fetches the flags of the message.  Returns a table of strings.

       fetch_date()
               Fetches the internal date of the message.  Returns a string.

       fetch_size()
               Fetches the size of the message.  Returns a number.

       fetch_structure()
               Fetches the body structure of the message. Returns a table that has as  keys  the  parts  of  the
               message, and as values a table that has one mandatory element, the type (string) of the part, and
               two optional elements, the size (number) and name (string) of the part.

   APPENDING
       The following methods can be used to append a message to a mailbox:

       append_message(message)
               Appends the message (string) to the mailbox.

       append_message(message, flags, date)
               Appends  the  message (string) to the mailbox, setting the specified flags (table of strings), as
               returned by fetch_flags(), and date (string), as returned by fetch_date().

       Examples:

           myaccount.mymailbox[2]:fetch_message()
           myaccount.mymailbox[3]:fetch_field('subject')
           myaccount.mymailbox[5]:fetch_part('1.1')

           myaccount['mymailbox'][7]:fetch_message()
           myaccount['myfolder/mymailbox'][11]:fetch_message()

           myaccount.mymailbox:append_message(message)

FUNCTIONS

       The following auxiliary functions are also available for convenience:

       form_date(days)
               Forms a date in “day-month-year” format that the system had before the number of  days  (number),
               and returns it as a string.

       get_password(prompt)
               Displays  the  specified prompt (string), and reads a password, while character echoing is turned
               off.  Returns that password as a string.

       become_daemon(interval, commands)
               Detaches the program from the controlling terminal and  runs  it  in  the  background  as  system
               daemon. The program will then repeatedly poll at the specified interval (number) in seconds. Each
               time the program wakes up, the commands (function) are executed.

       become_daemon(interval, commands, nochdir, noclose)
               Detaches  the  program  from  the  controlling  terminal  and runs it in the background as system
               daemon. The program will then repeatedly poll at the specified interval (number) in seconds. Each
               time the program wakes up, the commands (function) are executed.

               If nochdir (boolean) is “true”, the  current  working  directory  is  not  changed  to  the  root
               directory  (/).  If noclose (boolean) is “true”, the standard input, standard output and standard
               error are not redirected to /dev/null.

       pipe_to(command, data)
               Executes the system's command (string) and sends the data (string) to the standard input  channel
               of the subprocess. Returns a number, the exit status of the child process.

       pipe_from(command)
               Executes the system's command (string) and retrieves the data from the standard output channel of
               the subprocess.  Returns a number, the exit status of the child process, and a string, the output
               of the child process.

       regex_search(pattern, string)
               Implements  Perl-compatible  regular  expressions (PCRE). The pattern (string) is a PCRE pattern.
               The string (string) is the subject string in which the pattern is  matched  against.  Returns  at
               least  a  boolean, that denotes if the match was successful, and any captures which are of string
               type.  Note that due to Lua using backslash ‘\’ as an escape character for its strings,  one  has
               to  double backslashes in order to insert a single backslash inside a regular expression pattern.
               For more information on PCRE see http://pcre.org/original/doc/html/.

       Examples:

           date = form_date(14)
           password = get_password('Enter password: ')
           become_daemon(600, myfunction)
           status = pipe_to('mycommandline', 'mydata')
           status, data = pipe_from('mycommandline')
           success, capture = regex_search('^(?i)pcre: (\\w)$', 'mystring')

EXAMPLES

       See samples/config.lua and samples/extend.lua in the source code distribution.

ENVIRONMENT

       HOME    User's home directory.

SEE ALSO

       imapfilter(1)

Debian                                            Nov 11, 2017                              IMAPFILTER_CONFIG(5)