Answer
A remote system issued a VRFY command to GMS with a wildcard in it but GMS has been configured not to respond with any information. 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
558 Wildcard VRFY not allowed.
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.
See Also:
- 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 attack wildcard command not allowed 8106