[Mimedefang] Testing for port #/TLS in filter_relay

[Philip Prindeville]

I recently got one of those cool Nokia phones that does SMTP/TLS and 
IMAP4/SSL, so I figured I'd give it a try.

Unfortunately, when I connect to my mail server from Cingular, I'm going 
through a NATting proxy that uses an address block with no rDNS.

(Yes, I know that blocking incoming connections on the absence of rDNS 
is anti-social.  I've made my bed, and I'll lay in it...)

The issue is this:  if the user is connecting on 465 or 587 with SSL or 
TLS (resp), then we don't mind him not having rDNS because he has to 
authenticate with a username and password anyway.

So...  what can I test for in filter_relay() to know if the connection 
is coming in on port 25, or something else?

Thanks,

-Philip