Ordinarily, V8 sendmail sends notification of
failed mail to the envelope sender. It specifically does not send
notification to the addresses listed in the
Errors-To: header. It does this because the
Errors-To: header violates RFC1123. For additional
information about the Errors-To: header, see Errors-To:.
The UseErrorsTo option is available to prevent
older versions of mail-reading software from failing. When set, it
allows error notification to be sent to the address listed in the
Errors-To: header in addition to that sent to the
The forms of the UseErrorsTo option are as follows:
O UseErrorsTo=bool configuration file (V8.7 and later)
-OUseErrorsTo=bool command line (V8.7 and later)
define(`confUSE_ERRORS_TO',bool) mc configuration (V8.7 and later)
Olbool configuration file (deprecated)
-olbool command line (deprecated)
The optional argument bool, when missing,
defaults to true (errors are sent to the
Errors-To: header). If this option is missing
entirely, it defaults to false (the Errors-To:
header is ignored).
The UseErrorsTo option is not safe. If specified
from the command line, it can cause sendmail to
relinquish its special privileges.