[ILUG] sendmail not relaying for local(ish) clients

[David Ryan]

Hi all,

I have a sendmail server (latest version) which successfully accepts
mail from the outside world and allows users to pick the mail up over
POP3.

Clients can send mail to local addresses through the server but they
cannot send mail to the outside world - they get a '550 Relaying Denied'
message.

I know this is happening because of the spam prevention built into
sendmail, but what I don't know is how to tell sendmail to accept mail
for relay from the 10.0/16 subnet.  The sendmail server itself is in
10.1/16.  I know it's not a routing issue or anything like that since
the SMTP session is established correctly.

I put in an 'FR-o /etc/mail/relay-domains' entry and populated it with
both 10.0/16 and mydomain.ie, but neither of them worked.

Can anyone enlighten me please ?

Unfortunately linuxconf, install-sendmail and an alternative SMTP server
are not options.

Thanks,

David