I deleted about 2000 emails in Thunderbird, which is now nice and clean, but they are all still visible on the outlook.com web portal client.

I have Thunderbird configured using IMAP settings. I have Thunderbird set to move deleted items to the same folder outlook uses as trash. I emptied the trash also.

I would really like to avoid having to go through and delete them all in outlook as well. Is there a way to set Thunderbird to delete messages on outlook.com when deleted locally?

  • What sort of connection did you configure Thunderbird to use IMAP or POP3?
    – Ramhound
    Mar 5, 2013 at 21:07
  • 1
    @Ramhound - Check the tags: IMAP
    – Enigma
    Mar 5, 2013 at 21:08
  • I don't read the tags to clarify questions that should be written in a question. If a question contains specific details then the tags should reflect those details. Based on the original content I would have assumed you were using POP3. You should ask more detailed question in the future.
    – Ramhound
    Mar 6, 2013 at 12:23
  • 1
    Because you would delete emails client side and they were not being deleted on the server.
    – Ramhound
    Mar 6, 2013 at 15:33
  • 1
    @Ramhound - The default function of POP3 is to delete mails on the server when downloading them locally. The opposite is true for IMAP. You can't really assume in either case as they can both be set to work either way. Difference being, there would be no copy left on a POP3 server if set to pull & delete. I also had a Sync tag in there for this reason (IMAP).
    – Enigma
    Mar 6, 2013 at 15:39

2 Answers 2


Thunderbird does not delete messages from the POP server

  1. Go to Options -> Advanced -> Config Editor.

  2. Settings:

    • POP3 Find the Name mail . pop3 . deleteFromServerOnMove
    • IMAP Find the Name mail . imap . expunge_after_delete
  3. Set it to True.

True: Delete the copy of the message on the POP3 server if you move or delete the message.

False(default): Only delete the copy of the message on the POP3 server if you delete the message.

That's it, restart Thunderbird. You need to press 'Get Mail' everytime you want to sync with the email server, in order for you to make sure messages in the application is in sync with the email server.

The following should be emphasized to realize the sync with the server. You will not see your server message disappear upon the initial Get Mail download (new messages downloaded). After you process your Inbox in Thunderbird by deleting/moving a new message, then do another Get Mail which will delete the new messages previously downloaded on the server (put in sync).

Note: If you have older messages in your Thunderbird Inbox, they will not be deleted from Server. Delete them manually from server. From then on, any new messages you download, then process (delete/move), and then do the sync by doing Get Mail again WILL be deleted.

  • It's IMAP, not POP and that item doesn't show up. I found expunge_after_delete though.. is that similar?
    – Enigma
    Mar 5, 2013 at 21:04
  • Incorporate that in the answer please for accuracy and I'll consider it solved - it works.
    – Enigma
    Mar 5, 2013 at 21:13

Some notes here for using Office 365 with Thunderbird in Linux

Changing the Trash folder in Thunderbird from:

Trash => Deleted Items:

  • Open Thunderbird
  • Go to the Tools menu, and choose Options.
  • Go to the "Advanced" section and the "General" tab. Hit the "Config Editor" button located next to "Advanced Configuration".
  • Now you need to do some research hereto find which server you need to modify. Use the filter input box at the top, type in mail.server.server and you will see the list change and narrow down. This is a list of preferences and their associated values. One of these will be mail.server.serverX.name, where X is a number and the value is the name of the IMAP account you want to adjust the Trash folder for. Remember X because you need it to create the preference in the next step.
  • You can Right-click in a empty space in the list and select New->String from the shortcut menu.
  • You will be prompted for the name of your new preference. Put in mail.server.serverX.trash_folder_name, where X is the number you took note of from above.
  • After this a new prompt will ask you for the value of the preference. Put in the name of the folder as it is on the server. If it is a nested folder be sure to have the full path to the folder.
  • Close any remaining dialog boxes and restart Thunderbird for the changes to take effect.
  • Create a test message and delete it to verify that it is being sent to the correct folder on the server, and in Thunderbird.

  • In the config editor I also toggled to true:



  • & added a boolean true value for:


For Microsoft Exchange Calendar functionality in Linux I built & installed this Exchange Calendar plugin for Thunderbird.

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