NOTE: This tutorial is aimed at Ubuntu users.
- Open the home directory
- Select you’re username
- Press CTRL+H together to reveal hidden files and folders and locate .mozilla-thunderbird and .evolution
- Copy everything from ~/.mozilla-thunderbird/zyx.default/Mail into~/.evolution/mail/local/Inbox.sbd/ NOTE: Copy only the .mbox files and delete.msf files.
- Restart Evolution Mail and all you’re mails should be there.
NOTE: This is a short and easy solution if you have lots of folders in Thunderbird.