Ignore specific E-mail addresses

Hello.
I would like to know how I can choose to ignore a specific e-mail address in the E-mail scan.

We have a central printer at our office which also scans and sends the files in PDF format to clients, workers etc…

one of our users (this only seems to happen to one) keeps getting a warning when receiving a file from the machine. What can I do to fix this without dropping security or stopping the provider?

Thank you very much

The client has Avast Pro with all latest updates, Windows XP with all service packs and updates, and using Outlook 2003.

There isn’t a function to ignore a specific email address.

More importantly, what is the warning ?
I suspect a Suspicious Message alert (heuristics of email scanner) and that allows for the inclusion of a permitted URL in the Heuristics settings. That is of course it is a the message warning. The suspicious message warning would also say what is suspicious, it is this that is needed to identify the true problem.