- Added import from Thunderbird, and Mail archived mailbox

- When importing a PowerMail Exchange file that contains the folder hierarchy, the imported messages can either be merged in the existing folders (when they already exist), or can be saved in a new folder that will contain the imported folders.

- When importing a PowerMail Exchange file, links between imported messages (show repy, show original message…) are now restored

- When importing messages, an option can now be set to ignore messages that already exist in the database.

- Importing messages is now faster, as the senders and recipients are no longer added to the address history when this feature is enabled for received and sent messages