KMail can not send emails from GMail account

view story

https://www.kubuntuforums.net – I was having Kmail working for several days until now. Very recently, the problem is happening when I am trying to send email from Gmail account using Kmail. I get a response as "Failed to transport message. Your SMTP server does not support PLAIN. Choose a different authentication method. The server responded Username and password not accepted. (I had also changed my gmail password recently, the new password has been inputted in the gmail account settings and I am able to download the incoming email messages using new password. Therefore, the change of password may not be a problem. T (HowTos)