OT submission port question

[Steve Campbell]

Sort of related to Mailscanner, but more sendmailish.

I've had to start using the submission port with authentication for our 
roaming sales staff (isn't it always the sales staff that causes 
problems?). I've basically just added the port 587 and indicated it 
needed authentication to my normal sendmail configuration. This 
eliminates outside users from using me as a relay but allows the sales 
staff to use our server as if they were on-site. No problem up to this 
point.

The main problem is that now these emails go through MS. And because I 
whitelist based on our internal IPs, these roaming IPs from which the 
sales staff is sending get trapped and quarantined  sometimes since 
they're treated as non-local senders.

Can someone make a recommendation on how to handle these roamers when 
using MS, please? Maybe a way to drop them into mqueue instead of mqueue.in!

Thanks

Steve Campbell