Encrypting An Email Using GPG (not PGP)

Our web site is hosted on our providers site where ASP is installed. On our
website, we generate an email containing personal data including credit card
info whenever someone orders a product on-line from us (we only do a
transaction per day avg.) Becuase the email contains credit card info, we
want to encrypt it. I have downloaded/installed and generated a private and
public key using GPG and have distributed the public key I generated to the
provider that is hosting our website. They have imported it onto their
system.

How can you generate an encrypted email using the public key on the
providers system , using ASP?

Currently we are simply generating a plain text email containing this data -
and this has to stop.