(optional) If defined, replaces the mail transaction MAIL
FROM:<> in outgoing mailing list mail.
This option is provided for
advanced users. Normally, the mail transaction MAIL FROM:<> is the error
handler of the Lyris Server, and error mail is defined by Internet standards as
going to this address.
If you change this setting, Lyris
will no longer receive error mail, and thus will no longer be able to
automatically process bounces, error messages, bad deliveries, etc.