Warning users about authentication failures

Hello.

Suppose you set up fetchmail to get messages fro a service (POP or IMAP) 
and it works; then something happens (e.g. the password expires) and it 
stops working.
While I (as the sysadmin) can see this in the logs, I wish the user who 
reads the emails was informed.
In the past this worked: he received a mail from fetchmail itself saying 
auth was failing and another mail when everything was solved.
However, this hasn't been working for me for some time (after some 
upgrade, I think, but without any change to configuration).

What are the requirements to have these informational messages?
Some setting? Some prerequisite?
Has anything purposedly changed? (I don't know since when, however... 
possibly several months).

  bye & Thanks
	av.