KDE5 Kmail does not send e-mail

I have used kmail for years without problems (that couldn’t be easily fixed, or worked around or tolerated) but now I’m stumped.

Whenever I tried to send e-mail, I got this error:

Sending failed:
Your SMTP server does not support PLAIN.
Choose a different authentication method.
The server responded: "5.7.0 Error: authentication failed: generic failure"
The message will stay in the 'outbox' folder until you either fix the problem (e.g. a broken address) or remove the message from the 'outbox' folder.

Now, fortunately, I run my own mail server. I can confirm that the server requires authentication and uses TLS. I know the server address well. The server has worked well for many years.

I found on the KDE forums to try to delete and recreate the sending account, I did, Before I deleted and recreated the account, I would get the above failure message. Now, I don’t get that message. The KDE forum also suggested deleting the running pop3 resources (which I found using “ps aux”) which did not solve the problem.

Any idea of what could cause this?

I do have a self-signed ssl certificate. Could that be the problem???

Thanks for any advice,
Mark

Obviously.
Sending emails has nothing to do with POP3 (which is for downloading received emails from the server).

Any idea of what could cause this?

Wrong authentification settings maybe?
Try something else than “PLAIN”.

Thanks. I changed the authentication to: LOGIN and I can send mail again. Strange, but true.I hope this helps other folks.

Mark

Well, the error message you posted did say:

Sending failed:

Your SMTP server does not support PLAIN.


Encountered some problems with Kmail sending mail when turning authentication on. Used akonadiconsole to kill existing Mail Dispatcher Agent and start a new one.