Weird problems with MMAIL

Fellow Midrange Geeks:

Anybody know what "QGATE@<server>.<domain>" could be, in the context of a bounce message resulting from something sent from an AS/400?

We got some bounces on messages we sent through MMAIL from our monthly invoicing system, that we were then able to successfully resend manually, and I've already asked Mr. Perotti about it, and it doesn't make a lot of sense to him, either.

The bounces seem to conform to the following pattern (I've censored the actual email addresses to "sender@xxxxxxxxxxxxxxxxx" and "recipient@xxxxxxxxxx"):

Subject: UNDELIVERABLE MAIL
Date: Tue, 1 Apr 2014 16:38:17 -0700
From: QGATE@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
To: <sender@xxxxxxxxxxxxxxxxx>



NOT ABLE TO DELIVER MAIL TO SOME/ALL RECIPIENTS.
REPLY CODES WITH FIRST DIGIT = '4' OR '5' ARE ERROR REPLIES.
ERRORS THAT DO NOT HAVE ERROR REPLY CODES MAY EXIST.

HOST venus NOT ABLE TO DELIVER MAIL TO FOLLOWING RECIPIENT(S):
<recipient@xxxxxxxxxx>
RETRIES EXHAUSTED WHILE ATTEMPTING TO CONNECT TO REMOTE HOST domain.

** TEXT OF MAIL FOLLOWS **

and what followed was essentially the same as we'd see if we did a "display source" on the original message.

"venus" is the AS/400 from which we're sending the automated invoices, and "venus.private.touchtonecorp.com" matches what we see in the CHGTCPDMN screen thereon. But I haven't a clue what "QGATE@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx" could be.

--
James H. H. Lampert
Touchtone Corporation