[RndTbl] Shaw now blocking SMTP port 25

Trevor Cordes trevor at tecnopolis.ca
Sat May 26 04:24:00 CDT 2007

> The way I got around this issue was by letting sendmail listen on port 25 as
> usual, but having a iptables rule that redirected all incoming connections on
> port 25000 to 25.

Hey, great idea, quick and easy and no sendmail voodoo.

iptables -t nat -A PREROUTING -p tcp --dport 27 -j REDIRECT --to-port 25

iptables appears to do the prerouting change first then run the normal
port 25 rules on the altered packet.  Perfect.

Then Outlook Express clients just change:

Tools -> Accounts -> <your mail account> -> Properties -> Advanced
-> change outgoing mail SMTP number from 25 to 27

iptables is my hero!

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