Not sure i this is an ISA issue or exchange issue but I will post it here to see what response I get:
We have a front end and back end Microsoft Exchange 2003 server configuration.
OWA and OMA/Active sync is published by our unihomed ISA 2006 web proxy server which is located in our DMZ.
Users connect to the front end Exchange server from mobile devices and everything appears to be working fine, synchronisation all works.
However, sometimes when a user sends an external email from their mobile device, the recipient receives a message with a blank body.
This only happens when sending emails externally. Emails sent internally are received fine. Even including an internal user on an external email has no effect, the internal user gets the email, the external user doesn't. When the sender looks in their sent items on their device, the full email is there, and when they look in the Sent Items of Outlook, the full email is there
We've turned off all anti-virus products on the servers, and other 3rd party products, and no change, it still sends blank emails.
I've connected to our OMA site and tried sending it directly from there, in case it's to do with the mobile device, but still the same thing is happening.