If you did not empty the trash and compact all folders you only have moved and deleted messages from the Inbox. Providers count message storage in ALL your folders.

Having said that, there has been a Compact bug where it falsely tell you to compact folders. I have not experienced it so I do not know if that is fixed yet.

Thanks for the reply.

i do believe it may be a bug. i've deleted and compacted multiple folders. including emptying the trash.

Is this a pop or imap mail account ? Is this a gmail account ?

Logon to webmail account and see if those emails have gone from the server. Are they still on server ?

If server has eg: Bulk Mail or Spam folder - Empty it.

If server has 'All Mail' folder, check to see if there area load of emails still in it which you expected to be deleted.

Perhaps, the compacting isn't really compacting - a bug as Airmail mentioned. When you compact it removes marked as deleted hidden emails.

Enable the 'Folder Pane Columns ' so you can select to see the 'Size' column for the folder. Size should reduce when compacting is done..

• 'Menu icon' > 'Options' > 'Layout' > select 'Folder Pane columns'
• Then select the 'Size' option from drop down - see image below.

First: Try repairing the folder

• Right click on folder and select 'Properties'
• click on 'Repair Folder' button
• click on Ok

Then perform the compact on same folder :

• Right click on folder and select 'Compact'

If this fails to work.... Uninstalling Thunderbird and reinstalling rarely fixes most issues in Thunderbird because the issue is not with the program, but with the profile. But if this issue really is being caused by a bug then perhaps a fresh install will work on this occasion. What version of Thunderbird are you using? the up to date version is at the following link, but if you require a different version let the forum know and we'll give you a link to it. https://www.thunderbird.net/en-US/thunderbird/all/