[Evolution] No Matter What I Try, Can't Move Thunderbird Archives to Evo

["Bill and Carol Yager" <cbyager sbcglobal net>]

My Evo version is:  3.30.1        and I am set up for POP3 using ATT.com serrver

I have many, many saved emails organized in hundreds of sub-folder hierarchies in Thunderbird 60.4.0.   I believe the Thunderbird formt is Mbox while the Evo system is using Maildir.

For two weeks I have been trying Evolution and really like the UI, but I have been unsuccessful in migrating the Thunderbird emails to Evolution.  There are far too many to use the GUI within Evo which only appears to move one file at a time.  Also, I have searched these mailing list archives for solutions and have tried them. No luck.

I have tried two methods:

1. Copied the Saved_Mail.sbd folder (my top-level saved mail folder) from Thunderbird

    Home\thunderbird\xxxxxx.default\Mail\Local Folders\Saved_Mail.sbd

   into the Evolution "local" folder resulting in

    Home\.local\share\evolution\mail\local\Saved Mail.sbc

2. Created a folder "Saved_Mail" using the Evolution GUI and then copied the contents of the Thunderbird "Saved Mail.sbd" over to the Evolution "Saved_Mail" folder. In addition to the copied files, I see the "cur", "new" and "tmp" files in the Evo "Saved_Mail" folder, indicating the Maildir structure.

Some people have mentioned that the file to copy over is the file within the Thunderbird "Saved Mail.sbd" folder that doesn't have any extension; "Saved Mail.  " in my case.  But, this file is empty (size = 0)??

What am I doing wrong?  Other people have mentioned that they have successfully moved a folder hierarchy over to Evolution.  Is it because Evo is now using a different email method than Thunderbird (maildir vs mbox)?  If so, how do I compensate for this?

Any help will be greatly appreciated.  Really want to move from TB to Evo.

Thanks,

Bill