TLS connection for outbound mail

the_gripmaster · 05-28-2009, 11:56 AM

I have set up my MX servers to receive incoming connections to port 25 using TLS. I have tested the TLS connections and it is handling incoming TLS connections for inbound email without any problem.

Now, I would like to make sure my MX servers connect to a certain domain (eg visa.com) using TLS connection for outbound emails, i.e. delivering emails from my MX servers to the MX servers of visa.com. How can I make sure my MX servers use TLS connection when delivering email to the visa.com domain?

I am using sendmail 8.13.8 on RHEL 5.2.

Thanks in advance.

unSpawn · 05-31-2009, 05:44 AM

IIGC you use "TLS_Srv:${domainname} ENCR:${portnumber}" in /etc/mail/access. Watch those caveats though. I wonder what happens when a MTA doesn't accept TLS. If there's no TLS it can't be mandated... Plus this only gets you channel integrity, right? It's not the same as using file encryption.