HP-UX sendmail issue

[gserra]

I have an HP-UX 11 system running our ERP application Epicor's Manage2000. We use sendmail for automated emails from Manage2000 for system events using an smtp relay to Office 365. It was working fine for quite some time until about 2 weeks ago we started receiving NDR's from microsoft for those system emails however the emails were actually being delivered. The email recepients address addresses are formatted as

"receipient@vicon-security.com"@rx3600.vicon-security.com and the NDR states:

Your message couldn't be delivered. The Domain Name System (DNS) reported that the recipient's domain does not exist.

One of my consultants believes microsoft may have changed somethig and the formatting out of sendmail may be causing this issue. Microsoft is less than stellar in addressing this issue. Any ideas out there? Thanks in advance...

[Steven Schweda]

   I haven't fired a sendmail in anger for decades, so I know nothing,
but...

> [...] The email recepients address addresses are formatted as
> "receipient@vicon-security.com"@rx3600.vicon-security.com [...]

   To me that seems to have too many "at" signs (and quotation marks),
and, around here, there ain't no "rx3600.vicon-security.com":

ITS $ nslookup rx3600.vicon-security.com
[...]
*** its.antinode.info can't find rx3600.vicon-security.com: Non-existent
 host/domain

   Who formatted that e-mail address?  Knowing nothing, I'd guess that
the quoted part was you you wanted, and someone is adding
"@<bad_domain>" to it.

   If all such messages suffer the same fate, then I'd tend to suspect
the sendmail configuration, but, if some get through, then I'd start
looking at the source of the addresses.  Are the quotation marks
spurious, and confusing to someone who thinks that:
      "xxx@yyy"
is a simple name, which needs to have:
      @rx3600.vicon-security.com
("@<my_own_name>") appended to it to make a real e-mail address?

   Assuming that "rx3600.vicon-security.com" makes more sense on your
LAN than it does in the outside world, is this a new job for "rx3600",
and that job was previously done by some other HP-UX system (perhaps
with a different sendmail configuration)?