Linux Mail Server Setup and Howto Guide

Is there a configuration setting that I can add to a mail server so that it doesnt delete the emails when a user downloads it from the server. I want to keep them in there for maybe 90 days and after 90 days they can deleted. So a user can use any machine to check their emails and not be stuck to 1 machine.

Hi consulta

Thanks will test the configs. Why I really needed this config was so that mail admins can monitor a catch-all account for emails in the domain. Now just need to find out how to create the catch-all account.

Just for clarity a catch all account will receive all emails to the domain that do not have an account for example mispelt email address but the domain being correct. At the moment the emails are just bouncing and log watcher gives a report.