Problem: An issue has been reported where Email Gateway will process an email and not create a case and will move the email to the processed folder. The Audit log will not report any errors during processing.
Resolution: Doing some research we found that this problem might be being caused by the email sender who is sending the email in Rich Text Format rather than HTML or Plain Text. To resolve this problem you have two options:
Do not send the messages using Rich Text Format or;
Uncheck the “Are linked resources (i.e. signature files)” in Gateway
The consequence of choosing number 2 is that signature files will end up appearing as separate documents.
The link where this research brought us was the following