[ale] AT&T blocked

[cfowler at outpostsentinel.com (Christopher Fowler)]

Many of our employees work from home and have AT&T DSL.  I did not want 
to have them run
one configuration in Outlook for home and another on the road.  Too much 
of a pain to administer.  We
configured all laptops to use port 26 on our mail server for SMTP.  On 
our mail server I used iptables
to map 26 back to 25

/sbin/iptables -t nat -A PREROUTING -p tcp -s 0.0.0.0/0  --dport 26 -j 
REDIRECT --to-ports 25

We use SMTP authentication to prevent becoming a relay and this setup 
seems to work well for us.

Chris