MercuryS: Receiving spam with blank mail from

MercuryS: Receiving spam with blank mail from

Post by a2zxyz » Sun, 14 Dec 2003 04:41:31

I have noticed that I periodicly receive spam from senders who omit
the mail from email address. Is there an option somewhere to reject
messages without a from address? Actually, I am kind of surprised
that the RFC even allows this condition.

Sample Log:
11:45:12.139: Connection from, Fri Dec 12 11:45:11
11:45:12.139: << 220-[munged] Mercury/32 v3.32 ESMTP server
11:45:12.219: >> EHLO<cr><lf>
11:45:12.219: << 250-[munged] Hello; ESMTPs
11:45:12.219: << 250 HELP<cr><lf>
11:45:12.409: >> MAIL From:<><cr><lf>
11:45:15.313: << 250 Sender OK - send RCPTs.<cr><lf>
11:45:15.384: >> RCPT To:<[munged]><cr><lf>
11:45:15.384: << 250 Recipient OK - send RCPT or DATA.<cr><lf>
11:45:15.454: >> DATA<cr><lf>

MercuryS: Receiving spam with blank mail from

Post by Fred Vile » Sun, 14 Dec 2003 05:20:47


I hope not, the result would be a broken email server.

It not only allows it, it specifies what it is intended to be used
for and *requires* mail servers to support it.

The null sender address (MAIL FROM: <>) tells the receiving MTA not
to send bounce/error messages to the sender. It is routinely used by
MTAs when sending delivery error and deferral notification messages,
to prevent error messages from generating further error messages.

- Fred