I generally disable the 'DSN' EHLO keyword on the inbound SMTP port.
$ postconf -P smtp/inet/smtpd_discard_ehlo_keywords
smtp/inet/smtpd_discard_ehlo_keywords = silent-discard,DSN,ETRN
$ postconf -P smtpd_discard_ehlo_keywords
postconf: warning: unmatched request: "smtpd_discard_ehlo_keywords"
postconf -P smtp_discard_ehlo_keywords
postconf: warning: unmatched request: "smtp_discard_ehlo_keywords"
$ postconf -p smtpd_discard_ehlo_keywords
smtpd_discard_ehlo_keywords = pipelining, chunking, silent-discard,
DSN, ETRN
$ postconf -p smtp_discard_ehlo_keywords
smtp_discard_ehlo_keywords =
This prevents my postfix from sending a DSN to a sender for email coming
to my sever from the internet. However I would like for my postfix to
send a DSN back to me (locally), for an email I'm sending out to the
internet via submission port 587 as an authenticated user. Is this
possible? Or does it have to be enabled both way or not at all?
