SpamAssassin Rule: MSGID_FROM_MTA_HEADER
Standard description: Message-Id was added by a relay
The Message-Id header appears above at least one Received header in the message. This is a good indication that the Message-Id was generated by a relay, rather than by the user agent. This may be an indication of poorly behaved mailing software.
The default scores for this rule can be found in the online list of tests.
Message-Id is defined as an optional field that should be present ( RFC 2822 sec 3.6.4).