Answer
A remote system issued an ETRN command to GMS with a line that is too long. GMS has rejected the command.
In this case session Undefined was processing a connection from the server/client at Undefined when it received the command
Undefined
so GMS responded with
500 Line too long.
This problem is most likely to be caused by someone who is attacking your system to attempt to find a weakness. This potential attack has been identified by GMS and ignored. To find out why this is being done, contact the owner of the IP address Undefined and ask them.
See Also:
- How do I contact the owner of a remote server?
- What options can other servers use to request email using the ETRN extension?
- How do alerts work?
- How do I contact the owner of a client?
- What is SMTP Response Code Theory?
- How do I get GMS to request email using the ETRN extension?
Keywords:ETRN attack line too long TURN RFC1985 8122