Someone out there mu st have had this issue before. we have just configured our 3825 router with the IOS firewall application using the SDM defaults to start with but have hit a few issuses with being able to access webmail applications. we are using NAT to get from a private to public network. All applications are getting through and returning as they should. However we are having issues with webmail ie Yahoo google and hotmail.
if we use the SDM_Medium, Yahoo mail works but hotmail and googlemail fail. if we use SDM_high then hotmail and googlemail work and Yahoo mail fail. i must not be the first person to encounter this. does any ideas on how to resolve our issue