SMTP, SNAT via irule

Hello, thanks for your answer but it seems not suitably for my issue (or I don't understand your answer)

I'll give you more information about that.

The mail relay server for the internal mail clients is 10.1.1.1 (smtp.office.local). The F5 performs a loadbalancing to 172.10.10.10 or 172.10.10.20 (pool members).

The next step is, one of those mail servers creates a "new" outgoing smtp connection to any public mail server. The mail servers default GW is 172.10.10.1 (F5 floating IP). In this case the F5 have to perform an Source NAT to deliver the mails.

That mean to following for outgoing traffic of 172.10.10.0/24:

1. to deliver an e-mail or other non local traffic => source NAT
2. receive any other traffic to the internal networks => no soure NAT

additionally... In my case the F5 replaces an firewall or router between the external network and the internal networks so I need to perform an normal IP Forwarding between those networks. I've read F5 can't forward IP packets by default (full proxy) and the recommended option is point 3

3 . wildcard vServers with type Forwarding (IP) for both sides ???

How can I realize that??? Other Suggestions are welcome

Thanks a lot