pymodmilter

A pymilter based sendmail/postfix pre-queue filter with the ability to add, remove and modify e-mail headers.

The project is currently in beta status, but it is already used in a productive enterprise environment which processes about a million e-mails per month.

Requirements

• pymilter https://pythonhosted.org/pymilter/
• netaddr https://github.com/drkjam/netaddr/

Configuration

The pymodmilter uses an INI-style configuration file. The sections are described below.

Section "global"

Any available configuration option can be set in the global section as default instead of in a rule section.

The following configuration options are mandatory in the global section:

• rules
  Comma-separated, ordered list of active rules. For each, there must be a section of the same name in the configuration.

Rule sections

The following configuration options are mandatory for each rule:

• action
  Set the action of this rule. Possible values are:
  • add
  • del
  • mod
• header
  Name of the header in case of adding a header, regular expression to match whole header lines in case of deleting or modifying a header.

The following configuration options are mandatory for an add-rule:

• value
  Value of the header.

The following configuration options are mandatory for a mod-rule:

• search
  Regular expression to match the value of header lines. You may use subgroups or named subgroups (python syntax) to include parts of the original value in the new value.
• value
  New value of the header.

The following configuration options are optional for each rule:

• ignore_envfrom
  Regular expression to match envelop-from addresses. The rule will be skipped if the expression matches.
• ignore_hosts
  Comma-separated list of host and network addresses. The rule will be skipped if the sending host is included here.
• only_hosts
  Comma-separated list of host and network addresses. The rule will be skipped if the sending host is not included here. If a is included in both ignore_hosts and only_hosts, the rule will be skipped.
• log
  Enable or disable logging of this rule. Possible values are:
  • true
  • false

Developer information

Everyone who wants to improve or extend this project is very welcome.