Most spam comes in with bad, non RFC-compliant formatting within the message. The messages are often deliberately malformed in order to bypass filters and content checking software.
Yes. Build 3136 introduces a new concept called Message Quality to GMS Anti-Spam. That is it provides a large number of optional checks that may be run against incoming messages.
These checks are based on malformed messages that we have commonly seen on our own mail servers. Care needs to be taken though to ensure that you do not block legitimate mail.
All messages rejected by the Message Quality checks are placed into the Quarantine folders on the server. These Quarantine folders should be checked on a regular basis for legitimate mail, and the checks you are using adapted appropriately to let legitimate mail through.
Message Quality checks are configured under GMS Anti-Spam > Content > Message Quality.
The system level Quarantine folder can be checked under Reports > Quarantine Report, while the domain level ones are checked using the similar report under the domain level of the administration interface.
Keywords:gms anti spam anti-spam antispam clock bad format non-RFC compliant