Ordinarily, errors are bounced to the
envelope sender. The Errors-To: header specifies
the address, or addresses, to which sendmail
should send additional notification of delivery errors.
The Errors-To: header is intended for use by
mailing lists to prevent errors in a list from being rebroadcast to
the list as a whole. For example, consider the mailing list
allusers. Mail that is sent to this list should
contain the following header lines:
The From: header allows reply mail to be submitted
for distribution to the list. The Errors-To:
header causes error notification to be sent to
allusers-errors so that the maintainer can fix any
errors in the list. The original sender also gets error notification
unless the mailing list software represents the maintainer in the
envelope (Section 13.5.1).
Under SunOS and V8 sendmail the
Errors-To: header is flagged in
conf.c with the H_ERRORSTO header flag (Section 25.6.10). This allows other headers to be declared in
that file as error redirect headers. Under pre-V8 SunOS
sendmail the Errors-To:
header is ignored if the error mode set by the
ErrorMode option is m
(See this section).
Under V8 sendmail the
Errors-To: header is ignored unless the
UseErrorsTo option (UseErrorsTo)
is true. It does this because the Errors-To:
header violates RFC1123. Errors-To: was needed
only to take the place of the envelope sender in the days when most
Unix delivery agents couldn't differentiate between
header and envelope.
The Errors-To: header should never be declared in
the configuration file.