Yes Paul, I was referring to the link indicated, however I have managed to resolve the problem. Senility figures into this. [:)] My port redirect was actually working okay. It helps though if the port one is redirecting to is opened to accept the connections. [:D] I opened 2525 in ufw and connects are now getting through to Mercury.

Through all of this though I came across something of interest. The highly recommended procedure for adding rules like this in Debian-based system is to utilize  /etc/init.d/local rather than an /etc/rc.local. Here's a link:

 https://help.ubuntu.com/community/RcLocalHowto

That's the routine I am using .

I also did alterations to the redirect sample line to fit my needs. Because I have several ethernet connections I specified the one I wanted it on. Also, I guess

REDIRECT --to 2525 works but I "think" it actually should be REDIRECT --to-port 2525

Here's what I came up with for myself:

iptables -t nat -A PREROUTING -i eth1 -p tcp --dport 25 -j REDIRECT --to-port 2525

 I have read the FAQ post "Instructions on how to get MERCURY working in Linux as a non-Root/non-Power User" but have not been able to get it to work. What linux flavor and version were those of you that made comments using?  It's always important to mention the flavor you're working with when giving instructions in linux. I am using Ubuntu 10.04. The instructions given surely aren't giving me redirection  from 25 to 2525 on an smtp connect to 25.

Are you referring to http://community.pmail.com/forums/thread/24479.aspx ?

iptables is the key and should be available in most flavours of linux.  I have it in debian so it should be standard in ubuntu as well - if not it should be simple to install.

What error are you getting?