GMS was operating the smart redirect rules and a rule matched that requested that the message should be redirected to another account.
The smart rules are processed in order until one of the rules are matched. Once a rule is matched it is immediately actioned and all processing of the smart rules are stopped for that message.
In this case, session Undefined was using the rule which matched the parameters
- Undefined = Source server/client IP address;
- Undefined = MAIL clause (the protocol FROM details);
- Undefined = Local IP address that the message was delivered to (this may be different for multi-homed systems); and
- Undefined = RCPT clause (the protocol TO details).