[ale] AT&T blocking 25

[Christopher Fowler]

We are back up in our office on AT&T and they are blocking 25.  I
thought maybe specifying their server as a smart relay would work but it
does not.
 
I have a sendmail server in our datacenter that requires authentication.
I would like it to be my smart relay for our office.

I've added an iptables rule on that server to route port 26 -> 25.  From
evolution I can send mail and I'm authenticating fine.  I need to
program one of our servers to use that machine as a smart relay.  Would
it be required to auth too?