1. Export your self-signed mail certificate in DER format using following command:
openssl x509 -outform DER -in mail.pem -out mail.der
2. Copy resulting file to some directory under document root of your HTTP server (does not have to be on the same machine). In my case it was done with the following command:
mv mail.der ~lord/public_html/
3. Add to /etc/httpd/conf/httpd.conf MIME-type definition for DER files:
AddType application/x-x509-ca-cert .der
4. Open Web browser on your Nokia phone and go to URL on which you published your certificate. You will see a warning about importing untrusted certificate, click "Save" to proceed.
5. Verify in your list of CA certifictates (Settings->Security->Certif. Management) that the certificate you just imported is present in the list of "Autority" certificates.
6. Select it in the list and in "Options" menu select "Trust Setting". On the screen which will appear "Internet" option should be set "Yes" while others should be "No".
You are all set! Now when ProfiMail connects to your mail server using that certificate, you wlll no longer get warnings.