server-configs/opendkim/opendkim.conf

##
## opendkim.conf -- configuration file for OpenDKIM filter
##
## Copyright (c) 2010-2015, The Trusted Domain Project.  All rights reserved.
##

##
## For settings that refer to a "dataset", see the opendkim(8) man page.
##

## DEPRECATED CONFIGURATION OPTIONS
##
## The following configuration options are no longer valid.  They should be
## removed from your existing configuration file to prevent potential issues.
## Failure to do so may result in opendkim being unable to start.
##
## Removed in 2.10.0:
##   AddAllSignatureResults
##   ADSPAction
##   ADSPNoSuchDomain
##   BogusPolicy
##   DisableADSP
##   LDAPSoftStart
##   LocalADSP
##   NoDiscardableMailTo
##   On-PolicyError
##   SendADSPReports
##   UnprotectedPolicy

## CONFIGURATION OPTIONS

##  AllowSHA1Only { yes | no }
##      default "no"
##
##  By default, the filter will refuse to start if support for SHA256 is
##  not available since this violates the strong recommendations of
##  RFC6376 Section 3.3, which says:
##
##  "Verifiers MUST implement both rsa-sha1 and rsa-sha256.  Signers MUST
##   implement and SHOULD sign using rsa-sha256."
##
##  This forces that violation to be explicitly selected by the administrator.

# AllowSHA1Only     no

##  AlwaysAddARHeader { yes | no }
##      default "no"
##
##  Add an "Authentication-Results:" header 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 to be added.

# AlwaysAddARHeader no

##  AuthservID string
##      default (local host name)
##
##  Defines the "authserv-id" token to be used when generating
##  Authentication-Results headers after message verification.

# AuthservID        example.com

##  AuthservIDWithJobID
##      default "no"
##
##  Appends a "/" followed by the MTA's job ID to the "authserv-id" token
##  when generating Authentication-Results headers after message verification.

# AuthservIDWithJobId   no

##  AutoRestart { yes | no }
##      default "no"
##
##  Indicate whether or not the filter should arrange to restart automatically
##  if it crashes.

# AutoRestart       No

##  AutoRestartCount n
##      default 0
##
##  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.

# AutoRestartCount  0

##  AutoRestartRate n/t[u]
##      default (none)
##
##  Sets the maximum automatic restart rate.  See the opendkim.conf(5)
##  man page for the format of this parameter.

# AutoRestartRate   n/tu

##  Background { yes | no }
##      default "yes"
##
##  Indicate whether or not the filter should run in the background.

# Background        Yes

##  BaseDirectory path
##      default (none)
##
##  Causes the filter to change to the named directory before beginning
##  operation.  Thus, cores will be dumped here and configuration files
##  are read relative to this location.

# BaseDirectory     /var/run/opendkim

##  BodyLengthDB dataset
##      default (none)
##
##  A data set that is checked against envelope recipients to see if a
##  body length tag should be included in the generated signature.
##  This has security implications; see opendkim.conf(5) for details.

# BodyLengthDB      dataset

##  Canonicalization hdrcanon[/bodycanon]
##      default "simple/simple"
##
##  Select canonicalizations to use when signing.  If the "bodycanon" is
##  omitted, "simple" is used.  Valid values for each are "simple" and
##  "relaxed".

# Canonicalization  simple/simple
Canonicalization relaxed/simple

##  ClockDrift n
##      default 300
##
##  Specify the tolerance range for expired signatures or signatures
##  which appear to have timestamps in the future, allowing for clock
##  drift.

# ClockDrift        300

##  Diagnostics { yes | no }
##      default "no"
##
##  Specifies whether or not signatures with header diagnostic tags should
##  be generated.

# Diagnostics       No

##  DNSTimeout n
##      default 10
##
##  Specify the time in seconds to wait for replies from the nameserver when
##  requesting keys or signing policies.

# DNSTimeout        10

##  Domain dataset
##      default (none)
##
##  Specify for which domain(s) signing should be done.  No default; must
##  be specified for signing.

Domain REPLACEME.TLD

##  DomainKeysCompat { yes | no }
##      default "no"
##
##  When enabled, backward compatibility with DomainKeys (RFC4870) key
##  records is enabled.  Otherwise, such key records are considered to be
##  syntactically invalid.

# DomainKeysCompat  no

##  DontSignMailTo  dataset
##      default (none)
##
##  Gives a list of recipient addresses or address patterns whose mail should
##  not be signed.

# DontSignMailTo    addr1,addr2,...

##  EnableCoredumps { yes | no }
##      default "no"
##
##  On systems which have support for such, requests that the kernel dump
##  core even though the process may change user ID during its execution.

# EnableCoredumps   no

##  ExemptDomains dataset
##      default (none)
##
##  A data set of domain names that are checked against the message sender's
##  domain.  If a match is found, the message is ignored by the filter.

# ExemptDomains     domain1,domain2,...

##  ExternalIgnoreList filename
##
##  Names a file from which a list of externally-trusted hosts is read.
##  These are hosts which are allowed to send mail through you for signing.
##  Automatically contains 127.0.0.1.  See man page for file format.

# ExternalIgnoreList    filename

##  FixCRLF { yes | no }
##
##  Requests that the library convert "naked" CR and LF characters to
##  CRLFs during canonicalization.  The default is "no".

# FixCRLF       no

##  IgnoreMalformedMail { yes | no }
##      default "no"
##
##  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.

# IgnoreMalformedMail   no

##  InternalHosts dataset
##      default "127.0.0.1"
##
##  Names a file from which a list of internal hosts is read.  These are
##  hosts from which mail should be signed rather than verified.
##  Automatically contains 127.0.0.1.

# InternalHosts     dataset

##  KeepTemporaryFiles { yes | no }
##      default "no"
##
##  If set, causes temporary files generated during message signing or
##  verifying to be left behind for debugging use.  Not for normal operation;
##  can fill your disks quite fast on busy systems.

# KeepTemporaryFiles    no

##  KeyFile filename
##      default (none)
##
##  Specifies the path to the private key to use when signing.  Ignored if
##  SigningTable and KeyTable are used.  No default; must be specified for
##  signing if SigningTable/KeyTable are not in use.

KeyFile /etc/opendkim/REPLACEME.private

##  KeyTable dataset
##      default (none)
##
##  Defines a table that will be queried to convert key names to
##  sets of data of the form (signing domain, signing selector, private key).
##  The private key can either contain a PEM-formatted private key,
##  a base64-encoded DER format private key, or a path to a file containing
##  one of those.

# KeyTable      dataset

##  LogWhy { yes | no }
##      default "no"
##
##  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.

# LogWhy        no

##  MacroList macro[=value][,...]
##
##  Gives a set of MTA-provided macros which should be checked to see
##  if the sender has been determined to be a local user and therefore
##  whether or not signing should be done.  See opendkim.conf(5) for
##  more information.

# MacroList     foo=bar,baz=blivit

##  MaximumHeaders n
##
##  Disallow messages whose header blocks are bigger than "n" bytes.
##  Intended to detect and block a denial-of-service attack.  The default
##  is 65536.  A value of 0 disables this test.

# MaximumHeaders    n

##  MaximumSignaturesToVerify n
##      (default 3)
##
##  Verify no more than "n" signatures on an arriving message.
##  A value of 0 means "no limit".

# MaximumSignaturesToVerify n

##  MaximumSignedBytes n
##
##  Don't sign more than "n" bytes of the message.  The default is to
##  sign the entire message.  Setting this implies "BodyLengths".

# MaximumSignedBytes    n

##  MilterDebug n
##
##  Request a debug level of "n" from the milter library.  The default is 0.

# MilterDebug       0

##  Minimum n[% | +]
##      default 0
##
##  Sets a minimum signing volume; one of the following formats:
##  n   at least n bytes (or the whole message, whichever is less)
##      must be signed
##      n%  at least n% of the message must be signed
##  n+  if a length limit was presented in the signature, no more than
##          n bytes may have been added

# Minimum       n

##  MinimumKeyBits n
##      default 1024
##
##  Causes the library not to accept signatures matching keys made of fewer
##  than the specified number of bits, even if they would otherwise pass
##  DKIM signing.

# MinimumKeyBits    1024

##  Mode [sv]
##      default sv
##
##  Indicates which mode(s) of operation should be provided.  "s" means
##  "sign", "v" means "verify".

# Mode          sv

##  MTA dataset
##      default (none)
##
##  Specifies a list of MTAs whos mail should always be signed rather than
##  verified.  The "mtaname" is extracted from the DaemonPortOptions line
##  in effect.

# MTA           name

##  MultipleSignatures { yes | no }
##      default no
##
##  Allows multiple signatures to be added.  If set to "true" and a SigningTable
##  is in use, all SigningTable entries that match the candidate message will
##  cause a signature to be added.  Otherwise, only the first matching
##  SigningTable entry will be added, or only the key defined by Domain,
##  Selector and KeyFile will be added.

# MultipleSignatures    no

##  MustBeSigned dataset
##      default (none)
##
##  Defines a list of headers which, if present on a message, must be
##  signed for the signature to be considered acceptable.

# MustBeSigned      header1,header2,...

##  Nameservers addr1[,addr2[,...]]
##      default (none)
##
##  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.

# Nameservers addr1,addr2,...

##  NoHeaderB { yes | no }
##      default "no"
##
##  Suppresses addition of "header.b" tags on Authentication-Results
##  header fields.

# NoHeaderB     no

##  OmitHeaders dataset
##      default (none)
##
##  Specifies a list of headers that should always be omitted when signing.
##  Header names should be separated by commas.

# OmitHeaders       header1,header2,...

##  On-...
##
##  Specifies what to do when certain error conditions are encountered.
##
##  See opendkim.conf(5) for more information.

# On-Default
# On-BadSignature
# On-DNSError
# On-InternalError
# On-NoSignature
# On-Security
# On-SignatureError

##  OversignHeaders dataset
##      default (none)
##
##  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.  See opendkim.conf(5) for more
##  information.

# OverSignHeaders   header1,header2,...

##  PeerList dataset
##      default (none)
##
##  Contains a list of IP addresses, CIDR blocks, hostnames or domain names
##  whose mail should be neither signed nor verified by this filter.  See man
##  page for file format.

# PeerList      filename

##  PidFile filename
##      default (none)
##
##  Name of the file where the filter should write its pid before beginning
##  normal operations.

# PidFile       filename

##  POPDBFile dataset
##      default (none)
##
##  Names a database which should be checked for "POP before SMTP" records
##  as a form of authentication of users who may be sending mail through
##  the MTA for signing.  Requires special compilation of the filter.
##  See opendkim.conf(5) for more information.

# POPDBFile     filename

##  Quarantine { yes | no }
##      default "no"
##
##  Indicates whether or not the filter should arrange to quarantine mail
##  which fails verification.  Intended for diagnostic use only.

# Quarantine        No

##  QueryCache { yes | no }
##      default "no"
##
##  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.  The filter must be compiled with the QUERY_CACHE flag to enable
##  this feature, since it adds a library dependency.

# QueryCache        No

##  RedirectFailuresTo address
##      default (none)
##
##  Redirects signed messages to the specified address if none of the
##  signatures present failed to verify.

# RedirectFailuresTo    postmaster@example.com

##  RemoveARAll { yes | no }
##      default "no"
##
##  Remove all Authentication-Results: headers on all arriving mail.

# RemoveARAll       No

##  RemoveARFrom dataset
##      default (none)
##
##  Remove all Authentication-Results: headers on all arriving mail that
##  claim to have been added by hosts listed in this parameter.  The list
##  should be comma-separated.  Entire domains may be specified by preceding
##  the dopmain name by a single dot (".") character.

# RemoveARFrom      host1,host2,.domain1,.domain2,...

##  RemoveOldSignatures { yes | no }
##      default "no"
##
##  Remove old signatures on messages, if any, when generating a signature.

# RemoveOldSignatures   No

##  ReportAddress addr
##      default (executing user)@(hostname)
##
##  Specifies the sending address to be used on From: headers of outgoing
##  failure reports.  By default, the e-mail address of the user executing
##  the filter is used.

# ReportAddress     "DKIM Error Postmaster" <postmaster@example.com>

##  ReportBccAddress addr
##      default (none)
##
##  Specifies additional recipient address(es) to receive outgoing failure
##  reports.

# ReportBccAddress  postmaster@example.com, john@example.com

##  RequiredHeaders { yes | no }
##      default no
##
##  Rejects messages which don't conform to RFC5322 header count requirements.

# RequiredHeaders   No

##  RequireSafeKeys { yes | no }
##      default yes
##
##  Refuses to use key files that appear to have unsafe permissions.

# RequireSafeKeys   Yes

##  ResignAll { yes | no }
##      default no
##
##  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).

# ResignAll     No

##  ResignMailTo dataset
##      default (none)
##
##  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.

# ResignMailTo      dataset

##  ResolverConfiguration string
##
##  Passes arbitrary configuration data to the resolver.  For the stock UNIX
##  resolver, this is ignored; for Unbound, it names a resolv.conf(5)-style
##  file that should be read for configuration information.

# ResolverConfiguration string

##  ResolverTracing { yes | no }
##
##  Requests enabling of resolver trace features, if available.  The effect
##  of setting this flag depends on how trace features, if any, are implemented
##  in the resolver in use.  Currently only effective when used with the
##  OpenDKIM asynchronous resolver.

# ResolverTracing   no

##  Selector name
##
##  The name of the selector to use when signing.  No default; must be
##  specified for signing.

Selector REPLACEME

##  SenderHeaders   dataset
##      default (none)
##
##  Overrides the default list of headers that will be used to determine
##  the sending domain when deciding whether to sign the message and with
##  with which key(s).  See opendkim.conf(5) for details.

# SenderHeaders     From

##  SendReports { yes | no }
##      default "no"
##
##  Specifies whether or not the filter should generate report mail back
##  to senders when verification fails and an address for such a purpose
##  is provided.  See opendkim.conf(5) for details.

# SendReports       No

##  SignatureAlgorithm signalg
##      default "rsa-sha256"
##
##  Signature algorithm to use when generating signatures.  Must be either
##  "rsa-sha1" or "rsa-sha256".

# SignatureAlgorithm    rsa-sha256

##  SignatureTTL seconds
##      default "0"
##
##  Specifies the lifetime in seconds of signatures generated by the
##  filter.  A value of 0 means no expiration time is included in the
##  signature.

# SignatureTTL      0

##  SignHeaders dataset
##      default (none)
##
##  Specifies the list of headers which should be included when generating
##  signatures.  The string should be a comma-separated list of header names.
##  See the opendkim.conf(5) man page for more information.

# SignHeaders       header1,header2,...

##  SigningTable dataset
##      default (none)
##
##  Defines a dataset that will be queried for the message sender's address
##  to determine which private key(s) (if any) should be used to sign the
##  message.  The sender is determined from the value of the sender
##  header fields as described with SenderHeaders above.  The key for this
##  lookup should be an address or address pattern that matches senders;
##  see the opendkim.conf(5) man page for more information.  The value
##  of the lookup should return the name of a key found in the KeyTable
##  that should be used to sign the message.  If MultipleSignatures
##  is set, all possible lookup keys will be attempted which may result
##  in multiple signatures being applied.

# SigningTable      filename

##  SingleAuthResult { yes | no}
##      default "no"
##
##  When DomainKeys verification is enabled, multiple Authentication-Results
##  will be added, one for DK and one for DKIM.  With this enabled, only
##  a DKIM result will be reported unless DKIM failed but DK passed, in which
##  case only a DK result will be reported.

# SingleAuthResult  no

##  SMTPURI uri
##
##  Specifies a URI (e.g., "smtp://localhost") to which mail should be sent
##  via SMTP when notifications are generated.

# Socket smtp://localhost

##  Socket socketspec
##
##  Names the socket where this filter should listen for milter connections
##  from the MTA.  Required.  Should be in one of these forms:
##
##  inet:port@address       to listen on a specific interface
##  inet:port           to listen on all interfaces
##  local:/path/to/socket   to listen on a UNIX domain socket

Socket inet:8891@localhost

##  SoftwareHeader { yes | no }
##      default "no"
##
##  Add a DKIM-Filter header field to messages passing through this filter
##  to identify messages it has processed.

# SoftwareHeader    no

##  StrictHeaders { yes | no }
##      default "no"
##
##  Requests that the DKIM library refuse to process a message whose
##  header fields do not conform to the standards, in particular Section 3.6
##  of RFC5322.

# StrictHeaders     no

##  StrictTestMode { yes | no }
##      default "no"
##
##  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.

# StrictTestMode    no

##  SubDomains { yes | no }
##      default "no"
##
##  Sign for subdomains as well?

# SubDomains        No

##  Syslog { yes | no }
##      default "yes"
##
##  Log informational and error activity to syslog?

Syslog          Yes

##  SyslogFacility      facility
##      default "mail"
##
##  Valid values are :
##      auth cron daemon kern lpr mail news security syslog user uucp
##      local0 local1 local2 local3 local4 local5 local6 local7
##
##  syslog facility to be used

# SyslogFacility    mail

##  SyslogSuccess { yes | no }
##      default "no"
##
##  Log success activity to syslog?

# SyslogSuccess     No

##  TemporaryDirectory path
##      default /tmp
##
##  Specifies which directory will be used for creating temporary files
##  during message processing.

# TemporaryDirectory    /tmp

##  TestPublicKeys filename
##      default (none)
##
##  Names a file from which public keys should be read.  Intended for use
##  only during automated testing.

# TestPublicKeys    /tmp/testkeys

##  TrustAnchorFile filename
##      default (none)
##
## Specifies a file from which trust anchor data should be read when doing
## DNS queries and applying the DNSSEC protocol.  See the Unbound documentation
## at http://unbound.net for the expected format of this file.

# TrustAnchorFile   /var/named/trustanchor

##  UMask mask
##      default (none)
##
##  Change the process umask for file creation to the specified value.
##  The system has its own default which will be used (usually 022).
##  See the umask(2) man page for more information.

# UMask         022

# UnboundConfigFile /var/named/unbound.conf

##  Userid userid
##      default (none)
##
##  Change to user "userid" before starting normal operation?  May include
##  a group ID as well, separated from the userid by a colon.

UserID opendkim