Incoming Port Translation

Unanswered Question
May 6th, 2010

I am trying to Resolve an email issue.  I have a hosted email server that users connect to using Outlook and Outlook express.  The ISP for most of the clients recently made a change that blocks outbound 25 traffic.  They only allow SMTP over port 587.  The email server is behind an ASA5510.  I need to Port translate the incoming connection that comes in on 587 and needs to be translated to port 25 so the server accepts those connections.  Anyone knowing how to perform that translation please let me know

I have this problem too.
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Federico Coto F... Thu, 05/06/2010 - 06:16


static (in,out) tcp x.x.x.x 587 y.y.y.y 25

The above rule says that when incoming TCP traffic destined to port 587 reaches IP x.x.x.x (public IP for the mail server), the firewall will translate that connection to y.y.y.y (internal or real IP of the mail server) on port 25

In this way, the outside users will connect to the public IP on port 587, but the traffic will be forwarded to the mail server on its regular port 25



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