[CentOS] rm user:group

I want to remove files but only if they are owned by a certain user and group.

Basically I have this:

find /var/spool/greylist -mmin +363 -exec rm -f {} \;

I want to make sure it only deletes files owned by mail.  Basically no
matter what weird characters are in the file names I want to make sure
it does not delete anything outside of /var/spool/greylist.  I can add
'sudo -u' to it but then my secure log gets filled with entries but
perhaps thats the only way to do it.

Matt