how to import postfix certificates into outlook

I am using Mandriva Linux 2009 ( perfect ISP Setup ). When my clients connect with mail server they have an information, that my server has untrusted certicate. I created smtp certificate and imported it into internet explorer.

openssl pkcs12 -export -in smtpd.crt -inkey smtpd.key -out OutlookSMTP.p12

But the message is still displayed. I think tat that I must export also pop3 certificate but I don't know how

 

Make the certificate trusted via your mmc.

 

They are already imported with MMC into Windows but they are still not acceptable. Outlook says that the server uses other coding method but any method is good.

 

What is the exact error ?