Look in the thunderbird source. The devs had to make a many hundreds of lines config for each mega-corp. So, yeah, the mega-corps are covered by major workarounds in major email clients. But for normal email clients it's very hit and miss.
And while OAuth2 is open it is a toolkit for making protocols, not a protocol. And each megacorps implementation is different and handled differently.
Comments
Look in the thunderbird source. The devs had to make a many hundreds of lines config for each mega-corp. So, yeah, the mega-corps are covered by major workarounds in major email clients. But for normal email clients it's very hit and miss.
And while OAuth2 is open it is a toolkit for making protocols, not a protocol. And each megacorps implementation is different and handled differently.