sendmail, 4th Edition

PostmasterCopy

Extra copies of bounce messages All versions

RFC2821 requires that all sites be set up so that mail addressed to the special name Postmaster^[404] always be successfully delivered. This requirement ensures that notification of mail problems can always be sent and successfully delivered to the offending site.^[405] At most sites, the name Postmaster is an alias to a real person’s name in the aliases file. Mail to Postmaster should never be ignored.

Ordinarily, notification of locally bounced mail and other mail problems is sent back (bounced) to the sender of the message. The local person in the role of Postmaster does not get a copy of local failed mail.

The PostmasterCopy option tells sendmail to send a copy of all failed mail to another person, often Postmaster. Under V8 and SunOS, that copy contains only the failed message’s header. Under very old versions of sendmail, that copy includes both the header and the body.

The forms of the PostmasterCopy option are as follows:

O PostmasterCopy=user               ← configuration file (V8.7 and later)
-OPostmasterCopy=user               ← command line (V8.7 and later)
define(`confCOPY_ERRORS_TO',user)   ← mc configuration (V8.7 and later)
OPuser                              ← configuration file (deprecated)
-oPuser                             ← command line (deprecated)

The argument user is of type string. If the argument is missing or if the PostmasterCopy option is entirely missing, no extra copy is sent. The default for the mc configuration technique is to not send an extra copy.

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