right click the account and select subscribe.

Is there anything resembling a deleted/trash folder you can subscribe to?

Hi Matt - not sure what you meant by "right click the account". I have only one account. I tried going to "Account settings" and under "server settings" where there are alternatives for "When I delete a message, move it to . . ." and changing that from "Trash" to "Archives", but that's also on the server and the messages just disappear. Where in Thunderbird should I "right click the account"? My e-mail account is through the University of Minnesota and is @umn.edu, but the University has outsourced all its e-mail to Google, so I assume it is now on Google's servers, although the outsourcing happened some time ago while I was still on my old computer, and the problem only arose now. Does that make a difference?

right clicking and selecting the account in the folder pane and selecting settings takes you to account settings. Even if you right click local folders.

However if you only have one account and it does not appear in the folder pane to right click, then it must be a POP mail account, so all bets are off.

Please add the troubleshooting information to your post To find the Troubleshooting information:

• Open Help (or click on three-line-icon and select Help)
• Choose Troubleshooting Information
• Use the button Copy to clipboard to select all. Do not check box "Include account names"!
• Paste this in your post.

Matt- I found "subscribe" but the Archives, Trash, Sent, and Drafts folders are the only ones available and they are already subscribed. By right-clicking on the "segal001@umn.edu" subfolder under the Trashcan icon, I can get to a "Retention Policy" and uncheck "Use account settings" and click the radio button "Don't delete any messages", but it doesn't help. Can this be one of those situations where the e-mail provider automatically erases the message completely when you click "Delete" and there's nothing I can do about it?

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gmail simply abhor permanent deletions. Even when you empty the trash mail remains in the all mail folder as gmail "archive".

Do you have a [gmail] folder as shown below.

My folder pane goes in this sequence: inbox / drafts / sent / archives (icon looks like your "All Mail" folder but never has anything in it unless I put it there by clicking the "Archive" button) / no Spam folder / Trash icon with 2 subfolders: 1 folder marked with my account name and 1 trashcan icon marked "Local Folders" / Outbox (never has anything in it) / icon with my account name / local folders that I have set up. Under the Trash icon, things that I delete from Inbox/Sent/Archives go in the folder marked with my account name (or they did before they started disappearing) and things that I delete from my local folders go into the trashcan marked "Local Folders". I don't know if it makes a difference in the behavior of gmail that I don't actually have a gmail account; my account is @umn.edu, but the University is somehow using gmail. The problem started before I downloaded 45.3.0; I was using 45.2.0. The one thing that makes me wonder if Thunderbird is doing this is that if I right-click on the Trashcan icon marked "Local Folders" I get a menu that includes the "Empty Trash" command, but if I right-click on the folder under Trash that is marked with my account name, that command is not included in the menu, even if I have dragged messages into that folder and I can see them there. That command always used to be there before this problem started. I am actually not sure if the problem started when I migrated to the new computer and installed 45.2.0, but I think if it had, I would have realized it sooner than I did, because I was particularly worried about migrating Thunderbird.

View menu (alt+V) > folders > all. (I think you are using i=unified at the moment)

Does that make your folders look like the image?

Keyboard shortcuts don't always work for me, but in the Thunderbird View menu, my view was set at Folders>Unified. When I go to Folders>All I get the following sequence: [my account name], then below (within) it Inbox, Drafts, Sent, Archives, and Trash (folder icon); then Local Folders and below that, Archives, Trash (trashcan icon), Outbox, and then the local folders I have made. I don't get anything that says gmail. But my account is not a @gmail account, it is a @umn.edu account, and I don't know on what servers everything is stored, but I do use the same password for Thunderbird that I use for access to restricted University pages, so maybe everything is still on the University's servers even though the incoming server name in "account settings" is imap.gmail.com and the outgoing server name is smtp.gmail.com? Could the University be applying its own rules and not Google's? (Although I've asked the University IT Help about this problem and they are usually very good, and they can't figure it out.)

Gmail do indeed provide "business accounts" which take your domain but use Gmail servers. So you have a Frankenstein's monster account that has all the foibles of a Gmail account but appears to be something else. I have one too, used in my workplace as a fallback when the main server is broken.

Your "Trash" may be called bin, deleted or similar. The lack of the "empty deleted" option suggests that where your trash is going is not the folder associated with Trash in Thunderbird.

Hi Zenos - yes, that makes sense, thanks. I assume you mean that the lack of the "empty deleted" option when right-clicking on the Trash folder means that according to Thunderbird there is nothing in the trash to delete (although in the folder with the Trashcan icon under "local folders", the "empty deleted" option is there whether there is anything in the local Trash folder or not, which is what made me think originally that this was a Thunderbird change). Indeed, deleted messages from my inbox have always gone to a folder called by my account name, instead of a Trashcan icon, but they used to stay there until I used the "empty deleted" option. Is there a way of finding out where the messages are going? I have tried to direct them to the "Trash on [my account name]" folder and also to "Archives" and "Sent" folders using Server Settings, but they don't show up in either place (the only options I have in Server Settings are things that are on the server where my inbox and draft folders also live. So clicking on "deleted" is telling something or other to delete the message completely, but only for deleting messages in folders that are on the server; deleting messages in local folders still behaves the way it always did. So maybe this is a server issue, which is why I thought Google might be doing it.

Not quite.

Thunderbird has a group of special folders - inbox, Sent, Junk, Trash etc. Each of these has its own particular icon and some features, such as "empty deleted" which appear in pop-up menus. Simply naming a folder "Trash" doesn't give it these special features. My guess is that when you delete messages, Gmail is putting them into one folder (well, that's an approximation because Gmail uses labels not folders, but the outcome is the same) and Thunderbird is using another. If so, the folder being used by Gmail is not designated a Junk folder in Thunderbird so doesn't offer the "empty me" option. Does this folder have the same icon as Trash folders that do work normally?

There is an add-on called Folder Flags which allows you to see and set the status of these special folders. An extra tab is added to the folder's Properties page. This would allow you to set whichever folder you want to use for trash. But do bear in mind that your trash might be being sent to a folder named "Bin", "Deleted" etc. and not necessarily "Trash".

Hi Matt and Zenos: thanks to both of you. Matt, you were right about Gmail keeping everything; if I access my mail through the University’s WebMail function, I can see an “All Mail” “folder” containing about 17,000 messages, including all my deleted messages. Zenos, you were right about the Trash that doesn’t seem to function as expected; it has a folder icon, not a trashcan. As I now understand the situation: My e-mail account was originally set up on Thunderbird when the University maintained its own e-mail system. At that time there was a Trash folder icon that was identified (“flagged”?) as legitimate trash (it was contained under a trashcan icon along with another trashcan icon for “Local Trash"), and all the deleted messages from my inbox and Sent box went into it, and it could be emptied. When the University transitioned to Gmail, I was still using the same system (OSX 10.5.8), and the Trash folder identification remained. At that time I believe OSX 10.5.8 was already obsolete and I could no longer upgrade Thunderbird. When I migrated everything to a new computer running OSX 10.10.5 and upgraded Thunderbird, my folder panel remained the same, so the Trash folder was still there, but it was no longer identified as legitimate trash in the new “hybrid” Gmail system. (When I used the View>Folders>All command as Matt suggested, and then went back to the Unified view, I could no longer see that Trash folder, although it is still there in the All view and on my account in WebMail.) Even on my WebMail account I can’t find anything called Bin, Deleted, or anything that might be an alternative Trash. So I think now I need to (a) find out where Gmail is putting the deleted messages, if it’s actually “putting” them anywhere except in All Mail, and how I access that; or (b) figure out how to “flag” something else as Trash; or (c) figure out how to recover deleted messages from All Mail. I think all of that has to be done at this end, but I am most grateful to both of you for explaining the situation to me, and I am going to increase my contribution to the Thunderbird Foundation next year.

P.S.: I take it back about the folder having disappeared. I just opened Thunderbird in Unified view, and until I log in there is a trashcan icon marked "Trash" containing two trashcan icons, one with my account name and one marked "Local Folders". As soon as I log in, the trashcan icon with my account name changes to a folder icon. But even if I don't log in and delete something, it disappears. So my original "solutions" still have to be pursued.

When you logon to webmail account via a browser, gmail offers the choice of selecting folders to allow for imap. I know you are not gmail, but as explained it may be using the same method. Can you confirm you have selected to allow the Trash or Bin (whatever that folder is called) to be seen in imap?