Problems with NAT smtp

[armando_atanacio]

Hi! I have problem with my smtp server. I need to migrate my service from box Linux to Fortigate 100E. In this moments i can to access to ports 25 and 465 using Virtual IP. My problem is when the emails get out to a external service. For this i am using IP Pool for using specific external IP and it works but the communication never finishes. Sniffering some traffic a i realized that the source port changes at the moment of comunication over port tcp-25 which is not the case with the port tcp-465. The Policy for output traffic using the IP Pool is the same for twice ports from the internal IP.

[ul]

The output external IP is: 187.190.112.103

The smtp external is: 187.141.83.210[/ul]

I attach one image with the traffic.

Could guide me in solving the problem?