Most are not sent encrypted. There might be some out there, but I haven't seen any yet.
The main thing that you've said that concerns me is when you've mentioned contact forms and credit cards in the same sentence. Please do not ever do send credit card information via email in any way, even if it is "encrypted". Yes I mean that to be bold. It's very important.
There's a few reasons for this. Firstly, email is inherantly insecure. Emails pass through many different servers on their way to their destination, and any of those servers can sniff the contents for details such as credit card details. It's not common, but it does happen. The other thing to consider is that harvesting credit card details via email is normally against the terms of service of every merchant account that I've seen, so if your bank ever finds out that you (or even suspects you of) doing this they will close your merchant account immediatly. I had a client a few years back that had this happen so I know it's a very real possibility.
If you need to collect credit cards, get a real online merchant account and use that. Most have a page that you can direct to where they take care of the payment, some have an API that you can link into with some programming knowledge, and some have other options as well. If you're not doing big volumns, PayPal is one of the easiest ways to go, and these days probably one of the mroe well known ones.