kmail - where are the certificates stored

[Hans <hans.ullrich@loop.de>]

Dear debian users,

as I have some problem in kmail with TLS and smtp, I would like to delete the 
certificate for this special server without deleting the configuration for this 
server.

It would be nice, if you could tell me, where can I find the certificate(s) to 
delete this special one.

Thanks for the enlightening.

Best regards

Hans