Hi there,

I created a gmail account in kmail (after the 17.4.1 update in Neon), loged in with Oauth, synced, but when tried sending mail it asked for smtp passwrod, and gmail of course didn't accept it ("please log in with your browser"). Still have to enable unsafe applications in gmail to use kmail inspite of oauth supposedly working. Is it still broken?

Using XOAUTH2 to send mail isn't supported yet. Work is ongoing to provide it, probably in one of the next major Applications versions (17.08 or 17.12).

I am running 17.12.3 and it still does not seem to be supported. Or am I missing something in the settings? This feature is crucial, otherwise I cannot send emails. My email is not mandatory in 2FA, cannot turn "less secured apps" on anymore.

OAuth via SMTP (for Gmail only for now) has been merged into current development branch and will be available in the August release of KDE Applications.

This is great news, thanks.

Only it is end of September now and I didn't see it happen. Did something go wrong?
I'm on Neon user edition, just installed fresh to upgrade to the ubuntu 18.04 based version. So plasma 5.13.5, frameworks 5.50.0 and kmail 5.9.1.
As far as I can see, it didn't happen.

You need to manually change it in the settings. Go to Settings -> Configure KMail -> Accounts -> Sending, find your Gmail SMTP, click Modify and in the Advanced tab select the "XOAUTH2" authentication method. If you already use OAUTH for Gmail IMAP, sending should automagically work as well, otherwise you'll get the Google login window the first time you try to send an email.

Thank you for your reaction Daniel. And now I got it to work! Only it isn't so simpel.
I whiped out the folders .local an .config from another partition and started kmail again "from scatch" so to speak. It all went fine except for the smtp configuration. Kmail chooses automatically imap for my gmail (correct) but doesn't notice that I use "double verification". So I have to tell it by hand in the way you suggested. If I say "autodetect" in that dialog it goes wrong again. But when I say "OAuth" then close the window, open it again and THEN force autoconfiguration it works. And then it works without any problems.
Great! Thank you.