I do the following when I want to get a load of emails off the server to create space, but still want them visible in Thunderbird.

Make sure folders are Synchronised and set to download full copies of emails into all of the folders you require.

• https://support.mozilla.org/en-US/kb/imap-synchronization#w_configuring-synchronization-and-disk-space-usage

Then go into Offline mode. You could do this for each time :

• File > Offline > Download/Sync now
• select 'Mail Messages'
• Select 'Work offline once download and/or synch is complete'
• click on 'OK'

Or set up 'Offline' settings' to work automatically.

• 'Menu icon' > 'Options' > 'Advanced' > 'Network & Disc Space' tab
• click on 'Offline..' button

Download messages for offline use when going offline'

• select 'Yes'
• click on OK
• Click on OK

then when you go into offline mode via:

• File > Offline > work Offline

OR

• click on two blue screen icon in Status Bar

Folders will synchronise as per account settings.

Whilst in Offline mode - stops folders synchronising whilst moving a load of emails.

• Create suitably named folders in 'Local Folders' mail account.
• Select/Highlight emails in imap folder - suggest you copy in batches.
• Right click on highlighted emails and choose 'Copy to'.
• choose a suitable folder in your 'Local Folders' mail account.

Note: I suggest you use 'Copy to' instead of 'Move to' just in case email did not download fully for some reason. As a test: If you can read emails in Local Folders mail account then you have a good copy of emails.

At this point you could also make a backup of your Roaming/'Thunderbird' folder as it will contain everything, emails, address books, preferences etc etc.

Exit Thunderbird.

Access : C:\Users\<Windows user name>\AppData\Roaming\Thunderbird Copy the 'Thunderbird' folder to external drive or wherever you keep backups.

Start Thunderbird

Delete all the copied emails from your imap folders. Compact imap folders. Deleted emails should get removed from server thus increasing your quota. Full copies should be visible in 'Local Folders' mail account. Backup of emails are on external drive.

Thereafter if only moving the odd email off server, I still use 'Copy to' and select folder in 'Local Folders', but do not need to go offline - I only go offline when moving several emails. Check email is readible in Local Folders account, then delete the one in the imap folder. If email is not readible in 'Local Folders' mail account, then only the header was copied, so maybe it was not fully downloaded.

Thank you very much for that, all goes well EXCEPT deleting the emails.

If I try and delete more than 20 or so emails in Thunderbird it locks up and won't respond. Oh, well can still achieve the same by deleting from the server.

Thanks for the help

Phil