SMTP Server problem

[ATC]

We opened a second office and have a static VPN tunnel between a 100E and a 60E. Both firewalls are on firmware 6.0.2.

In all cases, traffic passes normally across the tunnel with the exception of fortigate email alerts. Email alerts generated by the 60E are not getting to our Exchange server at the 100E office. I've tried authenticated and no authentication. There are no errors in the logs. It is almost as if the fortigate email alert feature does not make use of the routing table, but I have no idea how to troubleshoot it. Would appreciate any suggestions.