I'm responding so other seeing this know this was posted twice and has been answered.

Thanks, David! I'm glad you are there to answer questions! But, I'm still stuck with the problem of losing so much. Why can't Thunderbird just send a text to me, on my iPhone, or iPad (photos) so that I can prove I'm really the legal guy for this account? Much easier than starting basically from the beginning. But thanks for what is currently possible. I'll try this. I hate to have to replace all my stuff!

   Best wishes, 
      Tom Luce

Thanks, David! I'm glad you are there to answer questions! But, I'm still stuck with the problem of losing so much. Why can't Thunderbird just send a text to me, on my iPhone, or iPad (photos) so that I can prove I'm really the legal guy for this account? Much easier than starting basically from the beginning.

You are only starting by re entering your password for the accounts, nothing else is lost.

However your comment about sending you the password is rather a common misconception, I assume generated by the fact web sites do it all the time.

The reality is Thunderbird stores your password file in an encrypted state. This is either based on a generic password I guess we can call it, or a primary password. As I am the only user of my password protected windows account on this machine, I do not use a primary password as it serves little purpose for me. My passwords are still stored on the local machine in an encrypted form, but decrypting them is fairly trivial.

You have chosen to store the file on your local hard disk using a primary password, this is something you chose to use to enhance the encryption of the password store. It is not sent anywhere, simply becomes part of your local Thunderbird install and is not actually stored anywhere that it can be accessed without the use of the primary password. If it was stored in an accessible location then it would obviously be no more secure that the passwords with the generic encryption. Hence it can not be sent to you because it is encrypted and can not be unencrypted with the password you no longer have.

The situation you are in is equivalent to you buying a combination padlock for your shed door, changing the combination and then forgetting what you changed it to. Writing to the company that made the padlock will get advice of the type "use bolt cutters" if you can not remember your combination. We are telling you much the same thing, you forgot the password that protects your password storage file, then we can delete it and you, as David explained, can enter those passwords again, but we can not recover them or the combination that accessed the file because we literally do not know it.

Matt your reply is pretty much above my level of computer technology. But I think you misunderstood my wish for simpler solution than using a "primary password" (which, by the way is what Thunderbird is insisting on have). I am used to other programs simply sending me a text or message to my iPhone and/or iPad which says is this you asking for help? And I click on "yes" and I'm allowed to proceed as the actual owner of the program/membership etc. etc.

    I wish that is what Thunderbird could do. I have used it for a few decades to promote a charity scholarship program for inner-city children in Port-Au-Prince, Haiti.  Now I can't use TB to send out newsletters, fund raising letters, etc. to our 186 supporters.  I have found that G-mail which I have used since th 80's has "mail merge" and now I'm trying to create an organization letterhead to use for sending the many newsletters. 
   Thank you, nevertheless Mat, I appreciate your attempt to help me. Hopefully you can continue to react to my pleading.
    Best wishes to you and yours!
           Tom Luce 510-575-6326.  tomfluce@gmail.com