re :I've recently been forced off POP into IMAP using OAUTH by google which now requires IMAP only with Google workspace emails.

I'm not so sure that's correct. This is the official notice from Google. Starting May 1, 2025, Google Workspace accounts no longer support less secure apps, third-party apps, or devices that ask you to sign in to your Google Account with your username and password. You must use OAuth to let these apps and devices access your account.

In Thunderbird, Pop accounts can also be set up to use Authentication Method: Oauth2. It's a very simple modification and Thunderbird set this up some time ago.

You may need to disable any program using localhost eg: Apache Xampp until all is set up. 1. Edit incoming and outgoing smtp 'Authentication Method' to use 'Oauth2' 2. In Thunderbird set up to allow cookies (Settings > Privacy & Security) 3. Remove the currently stored passwords in Thunderbird 4. REstart Thunderbird, enter normal password at prompt and then select to 'Allow' Thunderbird access to server.

Oauth2 token is stored in Thunderbird and will be used from then forth.

re : I will say that I miss POP because it allowed me to "catch" all my email in the gmail server, while using it as I saw fit on my TB/local computer. Now I'm required to mirror both - which is not helpful to me.

My previous comment was posted because it sounds like you really would prefer to use POP. I forget to say - do make sure you have enabled the POP option in the webmail account > SEttings > see all settings > Forwarding Pop/IMAP

Do you still have the Pop gmail account in your Account SEttings ? If you removed it, do you know that Thunderbird does not auto delete it from the Profile ? That means if you did remove it from Account SEttings, then you can create a new pop account using correct settings and then simply alter the 'Account SEttings' > 'Server Settings' > 'Local directory:' to point to the original pop folders and all your emails.

IMAP is designed to only display whatever is on the server as seen when you logon to webmail account. So, each folder synchronises with the server everytime you access the folder and move an email. If you choose to 'move' an email out of an imap folder then it also means you are 'moving' emails off the server. If something goes wrong then you stand a good chance of losing emails.

Many people have an Anti-Virus and that AV will scan incoming files /emails and it will also scan any file that gets opened. When the AV is doing this Thunderbird temporarilly has no access to a file. I would advise that you do not want any AV scanning your profile folders or their contents. Access AV and set up an exception to not scan your Thunderbird profile folder.

Just for good measure I'm going to post the full information on what checks to make on computer, in Thunderbird etc to set up to use Oauth for a POP gmail account.

If you use POP then make sure this set up in webmail account. In gmail webmail account - Settings > See all settings > Forwarding POP/IMAP tab make sure have enabled the POP option

Firewall: Access Firewall which may be controlled by the OS or by an Anti-Virus program you installed. Thunderbird must be set up as an allowed program.

VPN Please check computer and Anti-Virus product to see if a VPN has been enabled. Server does not like VPN, it will block access. So switch off VPN or create a split tunnelling and set up Thunderbird to use it.

'Localhost' If you use a program that uses 'localhost' - some people manage websites so might use something like Apache Xampp - Switch it off until Oauth has been set up.

In Thunderbird

• Settings > Privacy & Security
• WEb Content
• Select : 'Accept cookies from sites'
• Accept third party cookies 'Always'
• Click on 'Exceptions' button
• Set up: https://accounts.google.com as 'Allow'
• Click on 'Save Changes'

Scroll down to Passwords

• Click on 'Saved Passwords'
• Remove any line that mentions username = gmail email address you are trying to reset.
• Click on 'Close'

Check you are using correct gmail settings: Account Settings select 'Server SEttings' for the account POP:

• Server name: pop.gmail.com
• Port: 995
• Connection Security: SSL/TLS
• Authentication Method: Oauth2
• Username : full gmail email address

SMTP:

• Description: enter the same email address as shown in username (this helps you check you are using correct smtp when you have several gmail accounts)
• Server name: smtp.gmail.com
• Port: 465
• Connection Security: SSL/TLS
• Authentication Method: Oauth2
• Username : full gmail email address

EXit Thunderbird Wait a few moments for background files to update. Start Thunderbird

At prompt enter normal Password, then click on the 'Accept' to allow Thunderbird access to server.

IF you previously had a POP account and it's data is still stored in the profile.

• In Account Settings
• Select 'Server Settings' for the pop gmail account
• Look bottom right for 'Local directory:'

It is currently pointing to a new pop gmail account.

• click on 'Browse' button

It opens in a new window showing you contents of the current pop account which probably has a number appended to the name.

• Go up the directory to the 'Mail' folder and select the original pop gmail account folder.
• Click on 'Select Folder'

This will now force your new Pop account to use the original Pop account, so can see all your folders and emails.

I really appreciate the prompt and thoughtful reply.

You are correct that I can still use POP with my gmail and through Thunderbird.

I found that I had to start a new profile and authorize the account. My struggles arose from the fact that my older POP account could not simply be changed to OAUTH, and that all the gmail literature about the new changes refers only to IMAP in a way that implies its the only way.

Thank you for steering me back on course. I found the setup process through Thunderbird was perfectly easy and got me into the new account I needed.

We had a problem with Norton 360 AV and Thunderbird on 1 computer with an AOL account set to POP where Norton scanned and maybe quarantined an email causing the inbox to get messed up and the messages from that email that caused the problem and newer had parts of the email, maybe the subject and sender mixed up between them.

We solved the problem by adding an exception so the Thunderbird profiles are not scanned as suggested above and then set up our backup program Retrospect with a script to duplicate the TB profile to another folder and then run a custom scan with Norton. They say that Thunderbird cannot execute a macro like Outlook and really does not need to be virus checked but our method lets us scan occasionally without risking Thunderbirds emails if AV misinterprets something and quarantines something. Norton AV has never found a virus in the few years we have been doing this since the corruption so they are correct that you don't really need to scan but since we have the tools it gives a little peace of mind.

We had a problem with Norton 360 AV and Thunderbird on 1 computer with an AOL account set to POP where Norton scanned and maybe quarantined an email causing the inbox to get messed up and the messages from that email that caused the problem and newer had parts of the email, maybe the subject and sender mixed up between them. We solved the problem by adding an exception so the Thunderbird profiles are not scanned as suggested above and then set up our backup program Retrospect with a script to duplicate the TB profile to another folder and then run a custom scan with Norton. They say that Thunderbird cannot execute a macro like Outlook and really does not need to be virus checked but our method lets us scan occasionally without risking Thunderbirds emails if AV misinterprets something and quarantines something. Norton AV has never found a virus in the few years we have been doing this since the corruption so they are correct that you don't really need to scan but since we have the tools it gives a little peace of mind.

The problem is this - emails are stored in mbox text files that have same name as the folder you see in Folder Pane. That means one single mbox text file document might contain hundreds of emails, each one appended to the file as they were written to it. Anti-Virus has no concept of this. They see it as one file and if anything in the file is a problem, it can try to fix or quarrantine or even completely empty all the contents. But the end result is the file gets corrupted or killed and you lose some or all emails in that file.

Any email you think is dodgy - if you delete it and then compact the folder, all traces of that email are gone so there is no need to scan anything.

Scanning an mbox file is pointless as you have no idea whether the AV is picking up on a previously deleted email and traces still exist due to a lack of compacting OR if a dodgy email then you still do not which email.

If you do allow scanning - you must also set up to get AV to tell you there is a problem, but not auto fix - it must ask you what to do. In which case, you make a note of the file and you say do not do anything.

Sometimes the AV is picking up an email already deleted, but traces still exist because the folder has not been compacted. So, first action is to compact the folders especially the Inbox and the Junk/Spam folder.

If you really need to check further, then this is a procedure I use which identifies a specific email. However, I must admit in all the decades I've used Thunderbird - compacting Inbox and Junk has always proved to be the best method of cleaning up rubbish. But the following can help to identify a problem.

• Create a folder on desktop called 'TB-Check'
• In Thunderbird - select folder eg: Inbox
• click on first email and then use 'Ctrl+A' to highlight all emails in folder
• Right click on highlighted emails and choose 'Save as'
• In pop up window - select 'Desktop' to see list of folders it contains and then select 'TB-Check' so name appears in the bottom 'Folder: text area'
• click on 'Select folder' button
• All highlighted emails in the folder will get exported as single .eml files into the 'TB-Check' folder.
• Scan that 'TB-check' folder and see if he AV picks up on any file.

The difference is this - the *.eml files are individual emails, so now you have perfect control. Any particular email deemed as a no-go... Now you can go back into Thunderbird, locate that specific email in Inbox, delete it and then compact the Inbox to ensure all traces are gone. Finally go back to the 'TB-check' folder and delete the contents then empty the computer recycle bin to ensure all traces are gone or delete the bad eml file and then you have the choice to move all other .eml fles to a backup folder if required.