Hi!

Since a few weeks I have a problem with kmail (currently $ kmail --version: Qt: 4.5.2, KDE: 4.3.1 (KDE 4.3.1), KMail: 1.12.1): I always get the "Incorrect authentication data" error, when I try to send via the smtp server of one of my email providers.

Recieving mail via imap works, so I know the username and password are correct. Also it worked via kmail until some weeks ago. Sending and recieving mail from another provider works within kmail.

Sending via the problematic smtp account also works from Thunderbird. So I guess the problem is not on the provider side.

I already tried deleting that account and recreating it in kmail, to no avail.

Did you look at the encryption?
There is an option to test, what the server supports.

Yes, I tried with the autodetection and manually all possibilties.

Are you certain your isp actually uses authentication for outgoing mail? Many do not. Gmail does.

Yes. I've been using that accout (it's my uni) since years!

Hmm - if Thunderbird can send, but KMail can't, there has to be *some* difference in your settings. I can only suggest that you open your TB settings and write them down, then open your kmail settings and write them down. Notice that I didn't say compare them - it's too easy to see what you expect to see. If you make yourself write them down you may pick up something that otherwise you'd overlook. HTH

Do you use KWallet for saving the login data? Maybe there is a failure with saving the data?
Maybe try to don't save the password (I think there's a checkbox in the KMail configuration dialog).

Yes, i'm using kwallet, but the problem persits if I uncheck the "store password" option in kmail and enter it manually when sending.

Finally I deleted the whole kmail and kwallet configuration and started over from scratch. This time it works. I have no clue whats different this time and tend to think that it was sone kind of weird problem between kwallet and kmail.

Thanks for all your support!