[Users] Gmail OAuth2 Authorization Errors

[David Fletcher]

> * ?If you?re the app developer, make sure that these request details
>   comply with Google policies.
> redirect_uri: urn:ietf:wg:oauth:2.0:oob

Hi Dustin,

This error is because Google decided to deprecate a method of
authorisation which Claws Mail uses. They did this on Feb 22nd saying
that no new app registrations using that method are allowed, but
existing apps can continue to use the method until September.
Unfortunately since you're registering your ClientID with them after
22nd Feb they are seeing it as a 'new' application and disallowing the
authorisation.

The method isn't actually insecure in any real sense, but that's what
they've decide to do. They wrote a blog about it here:
https://developers.googleblog.com/2022/02/making-oauth-flows-safer.html

I'm working on an update - I posted the first code to fix this yesterday
on the Claws Mail developer list. However, that code was just a proof of
how to overcome the problem - it needs integration into the Claws
sources and testing to make sure it works properly. It's going to take
a little time to work through fixing this.

Are there other Gmail login methods open to you in the short term?

Best regards, David.