KMail refusing to send email after gssapi failure

I am using KMail 1.9.4 (KDE 3.5.4-25.el5_4.1 Red Hat). Our office
recently switched to smtp with GSSAPI authentication for sending mail.
As a result, mail sending in KMail became a serious problem. If for
any reason I forget to renew my ticket, KMail pops an error message
saying authentication failed. But after the ticket has been renewed
(and everything else relying on tickets is working just fine), KMail
just quietly refuses to send any email, keeping all my messages in the
inbox. I had a near-disaster when mail was not going out for two days,
and I didn't notice, just kept wondering why no one was responding to
my messages. I caught the problem more recently, but renewing
credentials, and even restarting KMail, was not enough. I had to
reboot the machine to make it happen.

Has anyone experienced this? How would I debug this? I tried googling
and KDE bugs, but cannot seem to find anything resembling my problem.

Myrosia