Managing Handlers

Handlers are managed - registered, updated, enabled/disabled and removed - with the mailmng utility. The utility stores information about registered handlers in files that are later accessed by the patched MTA or add-on to MTA.

A handler can be registered to be called in the following situations:

• For all messages
• For messages having specific sender or recipient address
• For messages having specific sender or recipient domain part of the address

For matching addresses, simple case-insensitive string comparison is done. It does not matter whether the specified domains or mail accounts exist in PPP.

The executable file specified for the handler must exist. If it does not exist, or is not executable, the handler is not called. The core is allowed to automatically remove handlers whose executable files do not exist, but it must not remove handlers whose files exist but are not executable.  

Each handler is identified by name. The name is a string unique among all registered handlers. It serves for both identification of a handler and ordering of multiple handlers applicable to a message.Handler names are not supposed to be human-readable.

The recommended pattern for a handler name is

<priority>-<component>-<unique>

Parameters

key

Prefix for ensuring the desired order of invocation. Must be a sequence of digits, presumably two. To have the handler called among the last, use a sequence of digits larger than in other handlers. The maximum digit is 16384.

component

Short name of the component, e.g., pmm.

unique

Any component-specific string which ensures uniqueness (and possibly sorting order) among multiple handlers installed by the same component.

For example, full handler name for Spamassassin is

10-spam-07dEOL