DKIM

This is the check module that performs verification of the DKIM signatures present on the incoming messages.

Configuration directives

check.dkim {
    debug no
    required_fields From Subject
    allow_body_subset no
    no_sig_action ignore
    broken_sig_action ignore
    fail_open no
}

Syntax: debug boolean
Default: global directive value

Log both successfull and unsuccessful check executions instead of just unsuccessful.

Syntax: required_fields string...
Default: From Subject

Header fields that should be included in each signature. If signature lacks any field listed in that directive, it will be considered invalid.

Note that From is always required to be signed, even if it is not included in this directive.

Syntax: no_sig_action action
Default: ignore (recommended by RFC 6376)

Action to take when message without any signature is received.

Note that DMARC policy of the sender domain can request more strict handling of missing DKIM signatures.

Syntax: broken_sig_action action
Default: ignore (recommended by RFC 6376)

Action to take when there are not valid signatures in a message.

Note that DMARC policy of the sender domain can request more strict handling of broken DKIM signatures.

Syntax: fail_open boolean
Default: no

Whether to accept the message if a temporary error occurs during DKIM verification. Rejecting the message with a 4xx code will require the sender to resend it later in a hope that the problem will be resolved.