This chapter contains descriptions of the following channels:

• the addressing channel ,
• the bitbucket channel ,
• the defragmentation channel ,
• the pager channel ,
• the pipe channel ,
• the printer channel ,
• the reprocessing and processing channels ,
• the "generic" SMTP channel , and

Note that some other miscellaneous channels can be found described in other chapters, such as:

• the conversion channel, described in Section 22.1,
• the directory channel, described in Section 3.2,
• the filter_discard channel, described in Section 16.2.5, and
• the mailserv channel, described in Section 4.3.