re :For a long time now (over a year) i had this problem where I can't delete the messages.

That seems a long time to put up with an issue.

1. What OS are you using?
2. What version of Thunderbird are you using?
3. Are you talking about a POP or IMAP mail account?
4. Are you able to emtpy the 'Trash' folder ?
5. Do you compact your folders on a regular basis? If no then do not compact just yet as there may be corruption in a folder. I'll offer advice on this when you repond with info.
6. Have you made a backup of your profile recently? If no then suggest you make a backup now.

re :For a long time now (over a year) i had this problem where I can't delete the messages. That seems a long time to put up with an issue.

1. What OS are you using?
2. What version of Thunderbird are you using?
3. Are you talking about a POP or IMAP mail account?
4. Are you able to emtpy the 'Trash' folder ?
5. Do you compact your folders on a regular basis? If no then do not compact just yet as there may be corruption in a folder. I'll offer advice on this when you repond with info.
6. Have you made a backup of your profile recently? If no then suggest you make a backup now.

1. Windows10
2. Version 68.9.0 (32bit)
3. Pop3
4. I can emprty the folder.
5. I compact the folders as much as I can
6. I have a backup from february, but good advice

Tidy up first:

• Empty the 'Junk' folder
• Right click on 'Junk' folder and select 'Compact'
• Right click on 'Drafts' folder and select 'Compact'

In Thunderbird

• Help > Troubleshooting Information
• click on 'Open Folder ' button

• Exit Thunderbird now - this is important

• Click on 'Mail' folder
• Click on 'pop account name' folder

• Delete the 'Trash' mbox file (no extension)
• If there is a 'Trash.msf' file delete it as well.

• Right click in blank area and select 'New' > 'Text document'
• Call it 'Trash' - it must be spelt correctly with a capital T

It will create file called 'Trash.txt'

• Edit the name so it only says 'Trash' - remove the dot and txt.
• You will get a pop up message warning about changing the extension, you need to allow it, so select Yes.
• Right click on the new 'Trash' file and select 'Properties'

Under 'Attributes'

• make sure 'Read only' and 'Hidden' checkboxes are not selected.
• click on Ok

Restart thunderbird.

Please test deleting an email. Post results.

Tidy up first:

• Empty the 'Junk' folder
• Right click on 'Junk' folder and select 'Compact'
• Right click on 'Drafts' folder and select 'Compact'

In Thunderbird

• Help > Troubleshooting Information
• click on 'Open Folder ' button

• Exit Thunderbird now - this is important

• Click on 'Mail' folder
• Click on 'pop account name' folder

• Delete the 'Trash' mbox file (no extension)
• If there is a 'Trash.msf' file delete it as well.

• Right click in blank area and select 'New' > 'Text document'
• Call it 'Trash' - it must be spelt correctly with a capital T

It will create file called 'Trash.txt'

• Edit the name so it only says 'Trash' - remove the dot and txt.
• You will get a pop up message warning about changing the extension, you need to allow it, so select Yes.
• Right click on the new 'Trash' file and select 'Properties'

Under 'Attributes'

• make sure 'Read only' and 'Hidden' checkboxes are not selected.
• click on Ok

Restart thunderbird. Please test deleting an email. Post results.

I dont have a "'Trash' mbox file (no extension)" so I skiped that step.

And now I can delete with DEL (hooray) but the Trash folder seems empty at all times (aaaw). (Thanks, I have posted for help in this past year but no one was able to help as far as you had.) Restarting didn't fix it. It is not good if the deleted mails get vanished from existence so easily, it might happen that I delete by mistake something I don't want gone...

Force a reindex repair.

In Folder Pane,

• Right click on 'Trash' folder and select 'Properties'
• click on 'Repair folder'
• click on OK

Force a reindex repair. In Folder Pane,

• Right click on 'Trash' folder and select 'Properties'
• click on 'Repair folder'
• click on OK

Nope, the messages go poof anyways. Funny thing is that I got the message to compact the trash folder even when nothing went inside.

Dscussiuon appear to be continung here as well https://support.mozilla.org/en-US/questions/1293317

Dscussiuon appear to be continung here as well https://support.mozilla.org/en-US/questions/1293317

Yes, sorry, close this one. The main question was answered.