IMAP is synchronized... you close the account with the provider and the next synchronization is account closed so the mail is deleted. You might not be liking it, but really it is happening exactly as intended. Just you did not think into the results of our actions.

Fortunately there is a solution to recover mail lost in those sorts of circumstances. but they involve moving the mail to Local folder which are not synchronized.

You however appear to be trying to create folders on the server by dropping them into the file system of the new account. That will not work. All that will happen is Thunderbird will synchronize with your gmail server and delete all the folders because they do not exist on GMail.

So is the issue mail or folders. Two entirely different things.

Well, as it turns out, the mail is NOT deleted, I erred in that... the "folders" are shown when opening the program, then disappear from the left window. The mail is still there, but cannot be viewed with TB under the Gmail server. I get all the mail just fine, AND, I can see all the filters (copied over from saved directory), so I guess I'll have to re-create all the folders to filter into and then point the filters to that new location? PIA...

My set-up was something like: INBOX --

  0 --
      A
          From A
          To A
      B
           From B
           To B
      C
 00 --
      A
          From... etc
      B
      C
  City --
      From City
      To City

etc. etc. etc

Matt sez: "You however appear to be trying to create folders on the server by dropping them into the file system of the new account. That will not work. All that will happen is Thunderbird will synchronize with your gmail server and delete all the folders because they do not exist on GMail."

Actually, no, I'm creating folders on my HDD, and enabling TB filters to put the incoming mail into the appropriate folders. The mail stays on the server, but is also d/l to my computer. Why TB won't recognize the folders on my computer, regardless of server, is the problem.

"Fortunately there is a solution to recover mail lost in those sorts of circumstances. but they involve moving the mail to Local folder which are not synchronized."

Copying individual messages and their .msf files to "Local Folder" works fine, but copying a Directory (xxx.sbd) with multiple directories inside (structured as shown above) with their .msf files does NOT work. Not seen by TB...

dkolars said

Copying individual messages and their .msf files to "Local Folder" works fine, but copying a Directory (xxx.sbd) with multiple directories inside (structured as shown above) with their .msf files does NOT work. Not seen by TB...

I think I already said that... It will not work. You can repeat it as many times as you like. It does not change the facts that dag and drop of folders does not work.

But, there is a difference between "Local Folders" and the normal Inbox, yes? When I copied to Inbox, TB would disappear them... I created all the mailboxes (Dir and sub-dir) in Local Folder, and that's working now. Now am re-doing all the filters... I NEVER used Local Folder when I was on Comcast.net. I left mail on their server, and copied it to my HDD in .thunderbird. Now that I'm on Gmail.com, that does not work. TB erases it from the Gmail Inbox. so, is that a TB or Gmail problem? It's working now, but not happy with TB... also, I had a set of toolbar add-ons to do things that should be available, like "Empty Trash", "Delete Junk", etc etc. Those have stopped working, as TB seems to have updated/changed. "Trash" is now called "Deleted", so wondering what else got changed. Grrr... Thanks for assist.

re :I had a set of toolbar add-ons to do things that should be available, like "Empty Trash", "Delete Junk",

RE: Addons: https://www.thunderbird.net/en-US/thunderbird/60.0/releasenotes/ IMPORTANT: Add-ons not marked as compatible with Thunderbird 60 by their authors will be disabled (this can be reverted via preference extensions.strictCompatibility) Suggest you try altering that preference in Config Editor to see if this gets those addons working again.

However, Account Settings already have the options to: Set how frequently you want to auto empty 'Junk'. eg: emails older than x number of days. You can also set up to auto empty Deleted/Trash folder on exit.

Note: Gmail can only delete emails off server (deleted from 'All Mail' folder) that have been put into the server subscribed 'Trash' folder or in some cases it is called 'Bin'. I have a imap gmail account and the server calls my trash folder 'Bin'. Make sure you really have subscribed to see the gmail trash folder, so it is visible in Folder Pane and you have set Account Settings to use it. Otherwise you may discover you are only deleting labels, so the 'All Mail' folder still has what you thought were deleted emails. Thus quota available on server will not have increased.

As a heads up, Gmail auto empties the Trash Bin periodically approx every 30 days. The 30 day count starts from when you put the email in it not from the date the email was sent to you.