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.)