iRule for SMTP: Passing Client IP Addr to backend mail servers

The SERVER_CONNECTED event is not needed.

One more thing. In the STREAM::replace command, only the replacement is needed.

STREAM::replace $replacment

Now test it by using a linux server behind a BigIP virtual and netcat such as in these examples.

http://stackoverflow.com/questions/8375860/echo-server-with-bash

You should be able to use telnet and type:

HELO 1.2.3.4

and it echos back "xxLO [your IP address]"