Mozilla Thunderbird Question

Question on behalf of a friend.

She uses Mozilla Thunderbird (latest version) to access her POP3 mail. Because she accesses her mail from more than one location, she has the checkbox for "Leave Mail On Server" checked.

This only seems to work when the messages are in her inbox. When she organizes her mail into folders in Thunderbird, it removes the mail messages from the server, seemingly ignoring the part where she specifically told it not to do that.

She wishes to be able to do both: Organize the messages into folders in her Thunderbird client, and also leave the mail on the server so she can access it from multiple locations.

Can this be done in Thunderbird via some secret option?

(Options she is not looking for at this time: Switching to Gmail, switching to a different mail client.)

POP3 only has the concept of a single Inbox, moving messages out of the Inbox is essentially deleting them and copying them locally to a folder. IMAP is the other major mail server type which has the concept of multiple folders existing on the server, and synchronizing them with clients.

Sometimes the host will provide both IMAP and POP3 servers on the same host. She could try setting the incoming mail server to be an IMAP server to see if that is the case. Otherwise, I can't think (off the top of my head) of an easy way to do it.

The option "Leave messages on server" has two sub options "For at most _ days" and "Until I delete or move from the Inbox".

She should decide what machine should handle all the deleting of mail from the server. On that machine check both options deleting after 20 days (If server quota is small she might need to lower this). On all other clients uncheck both sub options.

Thanks, guys.