Remote SMTP not working after upgrade to MS 4.79.11-1

[Roger Ide]

We can no longer remotely send email from external clients such as Outlook
via sendmail with MailScanner running, since an upgrade from MS 4.63.x to MS
4.79.11-1, also involving an upgrade to ClamAv 0.96.1, and SpamAssassin
3.3.0. This despite the fact that each user that is being denied access is
properly listed in /etc/relay-domains, and the /etc/mail/shadow, and
/etc/mail/passwd files. Saslauthd in running and testsaslauthd shows a
Success with a properly authorized user/password combination.

We're running EnsimPro Ensim Pro 10.3.0-fc.6.11, and everything was fine
before the upgrade. We have just the one website that we are hosting.
Sendmail, MailScanner and the rest are all located at the root level and
service the this one website which is 'site1'. The aforementioned
/etc/mail/shadow and passwd files are on at /home/virtual/site1/fst/etc.

With MailScanner off, sendmail has no trouble finding these files on its
own, and granting access to listed users.

With MailScanner running, sendmail does not seem to know where to look for
those files. The basic message I get is 'user information cannot be found'
(my paraphrase).

Experimentally, I copied the user data from
/home/virtual/site1/fst/etc/shadow into /etc/shadow, and did the same with
the passwd file user data. 

PRESTO! We are back to running normally. Except it's a fudge and the
question still needs answer.

Presumably the problem lies with the sendmail instances run by MailScanner
(or ClamAv or SpamAssassin), such that they no longer know where they
belong. Could this be a user/group issue, or the possibility that there is a
configuration that I have overlooked?

In order to deal with the multiple-recipient emails that we get, I followed
the suggestion at sendmail.org to set up a sendmail-in.cf (via a
sendmail-in.mc). This has been in place for over two years, so I haven't
considered it to be in the investigation stream. 

Additionally, it should be said that MailScanner upgrades have to be applied
outside the Ensim Pro environment since it was obsolecing even as we
acquired it on our 'new' server in 2007. I upgraded successfully to 4.63.x
at that time, but I may have had to make an adjustment at the time to avoid
this very problem. I don't remember that I had this problem, and I haven't
run across anything that would remind me of it. 

Thank you if you have read this far. If any of this rings a bell, or if
there is better information that I can provide, I will be happy to do so.

Roger Ide