My question is similar to this scenario but in our case we do not need to know the origin ip address so we will be doing SNAT automap. The SMTP servers would be operating as a SMTP relay on a dmz. Internal servers will send their smtp request to an F5 virtual ip address which will then loadbalance between pool members.
For the outbound request to the destination email server flow as described above it was our intention to have the SMTP servers simply point as their default gateway the Firewall address and have the firewall NAT to a single public address. This I think will avoid the reverse lookup issue described above. My question is what is "best practice" here? Is there any value added by sending the outbound flow through the F5? Any other issue we need to be aware of in setting up these SMTP relay servers?
Nimbostratus