Chapter 9. The Transports

Transports are the modules within Exim that carry out the actual deliveries. Some examples of transports have appeared in earlier chapters; in this chapter, we talk about the options that apply to all of them, and then consider each particular transport in turn. The available transports are as follows:

appendfile

A transport that writes messages to local files.

autoreply

A transport that generates automatic replies to messages.

lmtp

A transport that delivers messages to external processes using the LMTP protocol.

pipe

A transport that passes messages to external processes via pipes.

smtp

A transport that writes messages to other hosts over TCP/IP connections, using either SMTP or LMTP.

autoreply

Really a pseudotransport, because it does not actually deliver the message anywhere; instead it generates a new outgoing message (an automatic reply). It is included among the transports because its method of operation and configuration are the same, and it can include a copy of the original message in the reply.