An error occurred listing mail in this folder : Failed to connect to localhost:143 : Connection refused, I am getting this error when i log on to usermin. How do i correct it?

It sounds like Dovecot, your IMAP server, isn’t running.

You can fix that by logging in over SSH as root, and running:

/etc/init.d/dovecot restart

However, the fact that it isn’t running is a bit odd!

How much RAM is available on your system? You can determine that by running “free -m”. Sometimes, having too little RAM can cause daemons to stop working.

You can also get further clues by looking in /var/log/maillog or /var/log/mail.log, and look for errors relating to the Dovecot daemon.