Do internally generated messages get scanned by filters, anti-spam, or anti-virus?
Any internally generated messages do not go through the filter engine, or any other part of the "Per Policy" Scanning section of the email pipeline such as anti-spam or anti-virus.
Types of internally generated messages:
Alert messages are generated by the ESA to notify the designated recipient of changing status conditions on the ESA.
Notify messages are generated by the notify filter action. (These messages contain the full headers of an observed message but do not include the content of the message)
Bcc messages are generated by the bcc filter action. These messages are complete copies of the original message, which may include viruses or spam.
Bounce messages are generated by either filter actions, or failures during normal message delivery attempts.
An alternative to bcc is bcc-scan, which will send the message through the work queue like a normal message, scanning for both viruses and spam. However, they will not be sent through message filters again. This prevents potential delivery of viruses to the bcc'd address.
Cisco ESA Email Pipeline
For more information about message filter actions, see the AsyncOS for Email Advanced Configuration Guide :