BIG IP to load balance mail servers?

I recently purchased a Big IP LB with ver. 4.5.12 and have had no luck load balancing SMTP. I am trying to do the same setup described. So far, I created a pool with the SMTP servers (added in this format 10.0.0.x:25), no SNAT, no NAT and LB type is Round Robin. *LB and SMTP servers are on the same VLAN.

 

Then created a Virtual Server, with no Port or Address Translation and selected the SMTP Pool. Its been a while since I worked on one of these, am I missing a step or two, not doing it right?? Any help would be appreciated, I am on a time crunch.