I have an IMAP E-Mail account with my old provider.
I have a new, empty IMAP account with the new provider.
Is there a tool or Thunderbird to migrate the E-Mail data from one account to another? I'm a bit wary about just doing a drag & drop in Thunderbird because it's quite a lot of data, and I have a deep distrust against how Thunderbird deals with IMAP data.
I'm working on Windows 7, so I would prefer a graphical Windows tool. If need be, I can work from a Linux box as well.