Answer
A user has attempted to logon to GMS using the POP3 protocol using the APOP command but failed. The account exists, but the logon failed. The authentication failed because GMS was not able to obtain the password from the authentication source. APOP authentication requires GMS to obtain a copy of the user’s password in plain text in order to calculate the password digest. If the password is not available, it is not possible for any system to provide APOP authentication for users.
In this case, session Undefined was processing a connection from a client at Undefined. The user claimed to be Undefined@Undefined and attempted to log on with
Undefined
. The authentication was rejected with
-ERR User unknown
.
To resolve this problem you will need to check that the authentication source is available, can provide GMS with the password in plain text and the user has entered their details correctly. This error is not due to any failing of GMS but is due to the unavailability of the authentication source.
See Also:
- What password protection is there in #GMS#?
- How do alerts work?
- What is APOP authentication?
- How do I contact the owner of a client?
Keywords:failed logon POP3 APOP 8156