email authentication failure only on send

[pwabrahams]

I'm using kmail, with Comcast/XFinity as my ISP. Today I started getting repeated messages to the effect that authentication for sending mail has failed (failed to transport message) and most likely my password is wrong. I don't think the problem lies with Comcast, since (a) I can receive messages with no trouble, and (b) the problem showed up today even though I haven't changed anything, either in my kmail or Comcast settings. I can even log into my Comcast account and send messages from there. This has happened before, but I always was able to get past it by respecifying the password. Today that doesn't work. There's not much point in calling Comcast since they'll surely claim that my software is at fault, especially since the people there know nothing about Linux.

I've tried going into Configure Kmail/Accounts and respecifying the password. That doesn't help either.

[Snowhog]

In your Sending configuration, Advanced tab, what is Authentication set to?

[pwabrahams]

Problem cleared up by reboot (for now)

A reboot made the problem go away -- for now. My saved password was gone, so I respecified it. Authentication and save password are both checked. I'd be surprised if this problem doesn't show up again, though. It would be nice if I could kill it for good.

[SteveRiley]

If you show us how you've configured your outgoing account in KMail, we can double-check your settings. I use Comcast and haven't had a problem.