Due to Google restrictions we are forced to revert the way Aqua Mail handles OAUTH2 for Hotmail, Yahoo and Yandex. We will implement the new modernized OAUTH2 for them in the near future but it will take some time.
Now if you try to add Yahoo account, you should go to your web mail under Account Security and turn on the second slide box on the bottom right.
It sounds like you had to remove OAUTH for Yahoo / Yandex / Hotmail.
I checked the link, and to me it looks like Google's new requirements only apply to:
- OAUTH tokens obtained from Google
- Used to access user data residing on Google's servers
- In Google's services
I don't see (maybe I'm wrong) anything which would prevent you from using OAUTH tokens issued by _other_ mail services, to access user data residing on those _other_ servers.
Or is that the case? Maybe you could share more detail, don't think it would harm anyone or disclose "too much" since it's rooted in a document (that Google link) which is available to anyone.
Or drop me a personal email or maybe ask one of the developers to do this - I'm just curious, it seems so weird that Google would care about (and ask you to stop) the app using OAUTH with non-Google services.
Like I said, I'm genuinely curious about this one.