Sendmail, 3rd Edition

Delivery Agents by Name

As we have shown earlier, the MAILER command is used to enable a class of delivery agents. For example:

MAILER(`smtp')

This command causes support for the smtp, esmtp, smtp8, dsmtp, and relay delivery agents to be included in your configuration file. Further, the confSMTP_MAILER mc configuration macro can be used to define which one you want to use as your default outbound delivery agent:

define(`confSMTP_MAILER', `dsmtp')

Before you can choose a default, however, you need to know what each delivery agent does and how they differ. In this section, we describe these and all the other standard and special delivery agents. We describe them in alphabetical order, with a convenient summary shown in Table 20-1.

Table 20-1. Delivery agents described by name

MAILER( )	Agents declared	Description
cyrus	cyrus and cyrusbb (cyrus)	Deliver to a local cyrus user. Handles [e-mail] syntax to the user’s IMAP Vmailbox.
cyrusv2	cyrusv2 (cyrusv2)	Somewhat like cyrus, but delivers using LMTP via a Unix-domain socket, and requires Cyrus V2.
none	discard (discard)	Causes the message to be accepted and discarded.
none	error (error)	Causes the message to be rejected.
fax	fax (fax)	Delivers to a program that handles fax delivery.
none	*file* and *include* (*file* and *include*)	Performs delivery by appending to a file, and handle delivery through :include: lists.
local	local (See this section), prog (See this section)	Performs final, local ...