problem with kmail in kde3.1-alpha

I have been using kmail within kde3.1-alpha for a while without problems.  
Something happened which caused the following message box to pop up for both 
send and receive messages:

"The server certificate failed the authenticity test (server.name)"

I click OK then another message comes up to the effect

"would you like me to remove this error message forever ?"

I click "forever" and I can read or send the mail.

But, there is no forever, because the message keeps appearing.

I have checked with the postmaster of the ORNL mail server, and they have not 
changed anything recently from their end that could cause this, plus no one 
else is having similar problems.

How do I fix this problem ?

-- 
James D. Freels, Ph.D.
Oak Ridge National Laboratory
[email protected]