Answer
GMS has disconnected from the remote server because it is "Tar-pitting" GMS. What it is attempting to do is to cause GMS to run out of resources by holding connections open for as long as possible without accepting any email messages.
In this case, session Undefined was was processing a message to be delivered to the server Undefined (IP address Undefined). The local folder name is Undefined. The remote server has sent Undefined commands of which the last one was
Undefined
There is no problem with GMS, so no action is required by you. However, you may wish to investigate the problem with the remote server.
See Also:
Keywords:tarpitting tar-pitting disconnected 8389