Forum Discussion
Deb_Allen_18
Jan 19, 2007Historic F5 Account
SNAT replaces the client sourceIP.
X-Forwarded-For is an HTTP header than can be inserted in an HTTP request, but doesn't apply to SMTP traffic.
The best solution is to set the LTM floating self-IP on the mailserver-facing VLAN as the default gateway for the mailservers and disable the SNAT for the SMTP virtual server.
HTH
/deb