[fetchmail] Supress certificate warning

When i try to fetch post from one of my friends pop servers i get this error:
fetchmail: Server CommonName mismatch: IceWarp Software != foo.example.com

I know that this server don't have a trusted certificate because it is 
generated by the email software.
But are there any way in fetchmail that i can configure it to supress this 
warning, -s (silent) don't?
Best regards Henrik