Why am I getting an error “POP Lock” when I try to check my e-mail?

When checking your e-mail using webmail, it is possible to get the following message:

-ERR [IN-USE] .afarp.pop lock busy! Is another session active?

This error occurs when two different programs attempt to open your electronic mailbox. For example, you might have Outlook checking your e-mail every 5 minutes at home, while you try to open your e-mail (using Webmail) from work at the same time.

Another possible reason is that your Outlook crashed whilst trying to retrieve e-mail. In this case, your mailbox might have stayed open until it’s automatically closed a few minutes later.

A typical solution to this problem is to restart the program and/or the PC.