Re: [client] did not issue MAIL/EXPN/VRFY/ETRN during connection

Marco Moock wrote:

By default, sendmail logs the reported status code and DSN.
E.g.  reject=550 5.7.1 Rejected:
Maybe grep your logs for the error code they told you.

Absolutely nothing on my logs that remotely resembles the message they gave me (via another email provider):
"From MAILER-DAEMON@mx0a-0017d901.pphosted.com
Delivery is delayed to these recipients or groups:
user@domain.com
Subject: xxx
This message hasn't been delivered yet. Delivery will continue to be attempted.
Diagnostic information for administrators:
Generating server: mx0a-0017d901.pphosted.com
user@domain.com
Remote server returned '554 5.4.0 < #4.4.2>'
Original message headers:"
, followed by message headers starting at the machine attempting to contact my MX servers.
On my mail logs, all I have are entries as of this topic's subject: "[client] did not issue MAIL/EXPN/VRFY/ETRN during connection".
Claus Aßmann wrote:

So there is some "screwup device" in front of sendmail?
It's broken, get rid of it.
220 ***************************************************
That's an obvious violation of the RFC:
   Greeting       = ( "220 " (Domain / address-literal)

Odd - the obfuscation ("Mask server banner") is shown as disabled, but still being enforced. Can confirm via a packet capture from the external border router. I do not see any current bug that correlates to this, however I see other bugs that may cause drop of ESMTP connections within certain circumstances. Will review those with our security folks and possibly file a bug report, depending on the version of the security appliance, if a newer code version than the one running is not available.
So it may be my infra, after all... much appreciated for the insight again, Claus.