I think you need to reconsider your mail scanning. oAuth is not something that can be done by proxy. So this POPFile mail classifier will need to support oauth authentication in it's own right. As it has not seen an update in more that 12 years I doubt that will be happening.

https://sourceforge.net/projects/popfile/files/

Hey Matt, thanks for the reply.

Do you perhaps know of something I could use to fetch the mail (fetchmail comes to mind?) to transfer the email to another server (like my local server), then I could use POPFile to classify as usual, fetching from the local mail server instead. Do you or anyone else know of an OAuth2 capable fetchmail?

Another mail classifier might be an option too, though, ugh, the idea of losing decades of training POPfile seems.. not a good idea.

But Thunderbird POP accounts can use OAuth as follows:

Please note: If you run a localhost server eg: Apache then you will need to switch it off temporarilly to allow google to set up the token.

Thunderbird has made alterations so now both POP and IMAP accounts can use OAuth2 for gmail.

• Select 'Menu app icon' > 'Preferences' > 'Privacy & Security '

Under 'Web Content'

• Select 'Accept cookies from sites'

It may also be a good idea to make exception:

• Click on 'Exceptions..' button
• Enter: https://accounts.google.com
• Set to 'Allow'
• click on 'Save Changes'

Now make changes to Account Settings:

• Right click on gmail pop/imap account name in Folder Pane and select 'Settings'

This opens the Account Settings in new tab The pop/imap account name should be selected Look bottom right for Outgoing Server (SMTP)

• Click on 'Edit Server _SMTP' button
• Set Authentication Method : OAuth2
• Click on OK

Now set the incoming authentication:

• select 'Server Settings' for gmail account
• server name: pop.gmail.com
• Port: 995
• Connection Security: SSL/TLS
• Set Authentication Method : OAuth2

Exit Thunderbird and wait a few moments for background processes to complete Start Thunderbird

Gmail will prompt you to enter gmail email address and normal password you use to access webmail account. Follow instructions. It will ask this to allow Thunderbird to access server.

An Oauth token will get stored in Thunderbird - same place as passwords and from then onwards Thunderbird will use it to access server.

Thanks Toad-Hall, but this is not a solution to my issue.

As I wrote originally, OAuth2 + Thunderbird is fine. It's when I add POPFile into the mix, things become a problem.

Perhaps next time you can read the entire issue before replying. Thanks.

I read your issue and understood you were looking for a POPFILE that managed Oauth. I was offering the alternative normal method in case you decided to use it because POPFILE was no longer possible. But you do mention you already have Oauth working ok, so I see your point.

Toad-Hall: Perhaps you know of a 'fetchmail' tool I can use that supports OAuth2, which I could use to transfer emails from GMAIL to a different email server (like my own.)?

If I could transfer the emails out of GMAIL and into a local email inbox, then I wouldn't need OAuth2 in Thunderbird at all, since the emails would just be shoved into my local email server's inbox.