A remote system issued a VRFY command to GMS. GMS has searched the user database and could not find an account that matches so it has responded that there is no match for the string.
In this case session Undefined was processing a connection from the server/client at Undefined when it received the command
so GMS responded with
557 String does not match anything.
This problem is most likely to be caused by someone who is attacking your system in an 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. Configuring GMS to not respond to VRFY commands is recommended to help keep email addresses on your system private and secure.
- How do I contact the owner of a remote server?
- What is the SMTP VRFY clause?
- What is SMTP Response Code Theory?
- How do alerts work?
- How do I contact the owner of a client?
Keywords:VRFY does not match anything attack 8107