I am considering to change my windows desktop email client from Opera Mail (which I love, but which is abundant project) for The Bat!. The Bat is my first choice, but I need to migrate all email from Opera Mail. Can this be done? If not, I can migrate messages to Thunderbird. Can The Bat import messages from Thunderbird?
I just imported about 8000 messages fr om Opera 12.15 build 1748 to a new installation of The Bat! 8.5.8. They were all in the Unread mailbox.
I right-clicked on Unread in the list of mailboxes, clicked Export, and then exported to an MBS file (the only option). I believe I learned when I did this years ago that even though Opera uses its own extension (.mbs), the mailboxes it creates are in Unix format (usually .mbox). In any case, The Bat! can import them.
Do not use the Mailbox Wizard, which does not support Opera.
Unfortunately, you have to export each mailbox separately.
When you are ready to import into The Bat!, first click on the mailbox into which you want to import the messages. The Bat! does not ask you in the import process. I happened to have clicked on Sent, and so my 8000 messages were deposited there instead of where I wanted them, but it was a new install, so I could easily move them all.
Once you have clicked on the destination mailbox in The Bat!, click on Tools | Import Messages | From UNIX mailboxes...
Then navigate to the .mbs file you created in Opera and click on Open.
I was able to migrate the address book (contacts.adr) from Opera to The Bat! using the free tool at http://www.hallvord.com/opera/adr2tab.htm to convert the contacts.adr file. It worked better converting it to a .csv file. Then press F8 in The Bat! to open its address book and click on File | Import from | Comma-separated (plain text).
Just wanted to confirm that I was able to migrate emails from Opera mail (many accounts, more than 100.000 messages dating from 2002) to Thunderbird and from Thunderbird to The Bat. Thank you for your suggestions.