Imap accounts are designed to show what is on server. The imap folders synchronise with server folders. If you delete an email in an imap account eg: Inbox folder and it goes into the imap Trash folder, then the imap folders synchronise with server . In the case of gmail, the gmail server removes the 'Inbox' label and puts email in Trash and it removes email from 'All Mail' because you want the email deleted. After 30 days gmail will auto empty Trash.

If you only want to delete from the imap account, but keep email on server, then you can use a special shortcut method to by pass the Trash which means gmail will only remove the 'Inbox' label and archive the email in 'All Mail' folder.

To delete email by passing the Trash: Select email then hold down the 'Shift' key and press the 'Delete' key on keyboard.

Please note there is no Undo with this action.

Keyboard shortcuts: https://support.mozilla.org/en-US/kb/keyboard-shortcuts-thunderbird

Basically, the imap folders and the server folders are one and the same. Delete from either imap account or via webmail, it does not matter, the server gets updated with whatever you do in the imap account and vis versa. If you used webmail and deleted some emails, then when you start up Thunderbird you would find it connects to server and auto deletes emails from the imap account because they do not exist on server.

Thanks for clarifying this. If I change the Gmail account to POP, will this allow me to delete from Thunderbird without affecting the Gmail account on the server?

Thanks for clarifying this. If I change the Gmail account to POP, will this allow me to delete from Thunderbird without affecting the Gmail account on the server?

Yes.

Pop accounts can only access the server Inbox and download to the pop account Inbox. There is no synchronisation between any folder in a Pop account and any folder on the server. So this means the Pop account set of folders in Thunderbird can have different names from those on the server and contain different emails.

eg: The server may have all the emails in the Inbox because that's where all new incoming mail gets displayed. In Thunderbird, you can organise all those incoming emails into various folders. eg: Friends, Family, Bills, Online Orders, Clubs, etc plus the you will get the usual set of default folders. This organising is advised, so the mbox files that store the emails do not get too large. Note: the 'Sent' folder auto gets created when you first send an email, Same for Drafts etc.

Before you create the Pop account you need to make sure the webmail account has the correct settings set up.

• Logon to the gmail webmail account via a browser.
• click on 'Settings' gear wheel icon located top right
• select 'See all settings' from the pop up drop down section.
• Select 'Forwarding and Pop/Imap' tab
• For 'Pop download' section - select 'Enable pop for all mail'

Please note you cannot simply alter the server settings of the current imap account. You will need to set up the Pop account as New > Existing mail account.

After creating the Pop account in Thunderbird: check the 'Account Settings' > 'Server Settings' before downloading anything. Select 'Leave messages on server' The checkboxes below that setting offer some means of deleting off the server, but I do not believe the emails will be properly deleted because you are not able to put them in the gmail Trash. It means the label would get removed and gmail would still have the email in the 'All Mail' folder.

Gmail stores everything in the 'All Mail' folder; incoming, outgoing, archived - the lot. The use of 'labels' is like applying a tag which gmail uses as a search criteria so it can offer a virtual display of emails in a folder like structure which is easier for users to understand.

Gmail will auto empty the server 'Spam' and 'Trash' folder. So, if the server auto puts emails into the 'Spam' folder then Thunderbird cannot access them and you will not know what is in that 'Spam' folder unless you logon to webmail account.

Gradually, the number of emails on the server will increase. This will use up the quota on the server. If the server quota gets to maximun then the server will not be able to receive any emails until space has been created. Therefore I would advise, periodically, logon to the gmail webmail account and check the 'Inbox' for emails you may not need to keep OR check 'All Mail' folder for emails that do not have any labels (assuming you did select the option 'Until I delete' them).

Please note any emails you send using Thunderbird via the gmail server will get recognised by gmail and gmail will put copies of those sent emails into the server 'Sent Mail' folder. This is handy should you ever need to use webmail.

Your reply was clear and easy to follow. And it solved my problem perfectly.