Mail Error - AuthenticationFailedException: [AUTHENTICATIONFAILED] Invalid credentials (Failure)

[Deleted user]

I've reviewed all the posts & none of the suggestions worked. My incoming email was working at one time but now it is not. 

I get the error below when selecting the "Test Connection" button on on the Incoming Mail POP/IMAP Mail Servers. Help!  

AuthenticationFailedException: [AUTHENTICATIONFAILED] Invalid credentials (Failure) 

[Nic Brough -Adaptavist-]

I'm afraid this error is what it says on the tin.

The credentials for your email server are incorrect, and you need to provide the correct ones.

The most likely explanation is someone reset the password for acesupp, or triggered it to be locked out by attacking it.  Or the account has been disabled or removed by the email admins for some reason.