Okay, the simple approach is this - first, if not already installed, install the addon, importexporttools. It is a super tool to assist. - now, you need some basic technical ability to locate the desired folders in old pc. If thunderbird is still on old PC, do ths - click help>troubleshootinginformation - locate 'profile folder' and click 'open folder; - exit thunderbird - you are now inside the profile. I will presume the account is POP. - click Mail folder and you will see list of account names - click an account name and you will see its folders, such as inbox, inbox.msf, sent, sent.msf, etc. copy the desired folders to external media (the .msf files can be ignored) - now click the Local Folders folder and do the same here. If you see other folders such as xyz.sdb, click to see the files inside it. - now you have all the desired message folders on external media - on New PC, create a Local Folder for each of the folders you saved. Names may be different from original, if desired - now, highlight one of the newly-created local folders, rightclick, and select the importexport option to import mbox. Then seleck one of the files on the external media and click ok. - repeat the process for each item - when, done, I suggest doing a backup. if the profile is in the default location on Windows, I suggest this - exit thunderbird - copy c:\users\<yourid>\appdata\roaming\thunderbird to external media - now, if you have to restore, just copy the backedup thunderbird folder to c:\users\<yourid>\appdata\roaming to overlay existing thunderbird folder.

Hi David. Thank you so much for your quick response, and detailed instructions. I do flounder with techy stuff, but It looks as if I should be able to ..eventually, knowing me...follow your instructions. I am out tonight, so will have to put it to the test tomorrow. I greatly appreciated your kindess, and will re-post here if all goes well. Have a great weekend; Steve.

Hi David. Sorry. None of it worked at first (it said the XPI ) IXP I forget) file I wanted to install was corrupted) . I then found a different downlaod page that had the import export file but with the "NG" suffix, and it worked. I followed your (wonderfully clear!) instructions. I copied the folders to an sd card, and put the card in the new computer. I right clicked the new sb folders I had created t accept the old emails, and chose "import export, and then clciked on the corresponding OLd files I wanted to import. Nothing happened. Thyy do not show up. They ARE listed of course on the sd card, (see the screen shot..they are clesarly there and have KB to show the size of tfiles) ) but the import doesnt see them. I've seen that sometimes when, for example, you have jpeg files in a folder but the programme is looking only for (for example) .PNG files. I KNOW The files ARE on the sd card, as it shows them, But the import facilty cannot seem to see them. If you can think how to get over this LAST ( I hope) hurdle Id be SO grateful! Many thanks again Steve

Ok, I don't know what you're doing, but you're doing something wrong. Be sure you are at the 'import mbox' selection. It is not specific and will try to import whatever you select, so there are no conditions. Maybe if you copy one or two to your hard drive, you can import there and discover whatever the issue is.

Hi David. I really appreciate your bothering with me. My SD card clearly shows the various files I got from the Old Computer, thanks to your instructions. That seems to have worked fine. :) ( It also shows the amount of KB in the files) So far so good it seems.

I then open Thunderbird on the New computer, and I right click the first folder into which I want to import the old data. Please see the screen shot... no. 49. The folder in this example is "BIDDLES PO". This , again, seems to respond exactly as you said, and it opens the "import /export " dialogue , with "import exportNG" as the choice at the bottom of the list. So I seem to be so close! Then... see in the next screenshot no. 50....,... the ONLY option that is "greyed out" is ...."import mbox files". That is the frustrating last hurdle it seems. In depseration I tried "import EML files " just in case that was a "workaround", and when I broused to the sd card it showed completely blank. But the files ARE there if I double click the sd card as one would normally ....see screeenshot 37..... . So Presumably ONLY the "importmbox files" can see/read them, but that is as I say the one option that is greyed out. David, I am sure you must be busy, given your expertise, but if this information helps you to realise where it has gone wrong for me, or have some other "lightbulb moment" I would be so grateful. (as... I hear.. will my wife be!) SO sorry to trouble you, but I hope this explanation and the screenshots might help. Best wishes Steve.

My suggested steps were to import into local folders, but it seems you are trying to import into the account. Is the account IMAP? if so, you cannot import mbox files into IMAP. If this is IMAP, you can do that, but you mist first do the steps I suggested, and then you can either: - open all messages in each account, highlight them, right click and select the 'copy to' option. OR, you can - do the steps I suggested t Local Folders - then use the import/export addon to export as eml files to a folder outside of thunderbird and then use the import/export addon to import eml to the IMAP folders. Either way is problematic, since uploading to IMAP is not how IMAP is designed. You would need to spot check that the messages all upload completely. If your intent is to preserve the messages, saving in Local Folders and using a PC-to-cloud backup service may prove easier and safer.

Hi David.. My "info@address is IMAP. I only know that "IMAP" should mean my mail is still on my server after I download it. . HAD I know that before TSO "upgraded" my email I wouldnt be in this mess, as it was wet to POP. I am not technical.

I dont understand the difference between Local Folders and any other folders, I assumed thst Local Folders" were so called because they are on my computer as opposed to "in the cloud".

To prepare for the "Importing" of the old emails I right clicked my "Inbox" folder, and created the new folders as you said so as to have somewhere tio import the old emails to. I NOW see (duh!) ..right at the bottom of the page .."Local Folders"! ! If I repeat the creation of new subfolders, but this time I right click "Local Folders" and create them there istead of my Inbox will that help me mw forwards?? Or do I still need to overcome the fact that my mail is set to IMAP to avoid this disaster ever happening again? If you can reply to this , I am FULLY prepared to then "take it on the chin" if you then say .." but that's it Steve; you are clearly so useless at this that I can't help you any further!!"... I will understand, and still be very grateful for your time and effort to help me.

Once you get them to local folders, you can upload to the IMAP account, folder by folder. It's a lot of time commitment on your part, and that's why I offered the alternative of a PC-to-cloud backup service. If you upload, I suggest creating a filter to do that, as it slows the process somewhat for a more stable upload. Always use COPY. Then, when you're content that all is well, you could delete the local folders. l(And I've gone down deeper rabbit holes on this forum than this one. :)

Hi David. I cannot thank you enough. I must however tell you what is happening now.

Thanks to your clarification (that’s not an accusation; it would have been clear to a normal person originally!) I have created a new empty "test" folder in “Local Folders” on the NEW computer, (instead of in the “Inbox!”). Immediately, when I right clicked the new empty folder, the option of “Import mboxfile” WAS finally available! Not greyed out! Great. Thank you!

I then went to the OLD computer and tried to “shift/c” all the mail folders under “INBOX” to get them onto the sd card, so as to ferry them across from old comp to the new. However, it will only let me copy one folder to the SD Card at a time. Not a complaint; I’m glad to have achieved anything. (NOTE: IF any folder has an inner subfolder, it would NOT include the sub folder when I copied the “master” folder; I have to open the “tree” and click both the “master” AND inner subfolders in order to get each one onto the SD card. Having then got them all onto the SD card I then transfer the card to the New Computer, and open Thunderbird. From there I CAN “shift/c” multiple folders on the sd card, and import them to Local Folders en masse. Which speeds things up. The folders all appear under Local Folders, and arrive with their contents. Wonderful. (As I had previously (incorrectly) created new recipient folders in the Inbox, I can also drag the contents from the newly imported folders (In the Local Folders) into the ones I created in the Inbox. ) ( That may seem mad to you (?) but I’m just used to seeing them up there.)

All I need to do now... ( I think!) is to reunite the subfolders back into their appropriate “master” folder” and hopefully all is done. ! (So I didn’t need (it seems) to create any New Folders in readiness to receive; as the “import” action brought the old folders in complete with their contents. (I suppose it would be necessary if bringing in the individual emails, but that would have been confusing for me on the sd card) Likewise ..I still do not understand the IMAP issue, but suffice to say it all seems to have worked as I describe here, despite my having an IMAP address. I mention that not from any position of understanding, but it may be that a “tweak” has been created recently to avoid that issue, and if so it will perhaps affect any advice you give in future. Or of course, in my ignorance, that is yet to come back and bite me! .

Anyway; It SEEMS all is well now, and I would never have done it without your kindness and information (and patience!) SO very grateful to you. If you ever visit Norfolk I’ll buy you a beer. Have a great week/month/life. Steve (and Fiona! )

You are most welcome. i enjoyed the experience. :) Thank you for your kind words.