Problem: Trying to forward some pictures I took on my iPhone via email. The total size for the attachments was about 20MB. After sending I got the following error message:
“Cannot Send Mail: An error occurred while delivering this message”
“Cannot Send Mail: The message was rejected by the server”
Solution: I checked the exchange logs and got an Event ID 1008. The event talked about an outdated or corrupt partnership with my iPhone. I also noticed another messages stating the “Maximum request length exceeded” Which brought me to the solution. I followed the directions in the following Technet blog article(link below). Changed the <httpRuntime maxRequestLength=”10240″/> setting to “25600” or 25MB on my CAS server. Once the change was made, the emails passed without error.