I noticed that I never received an email sent through my contact form on our website. We have the domain on a shared server, through an ISP. Then today, a week later, I received it, and the header looks different than headers from other messages. Can someone tell me if the return path and envelope seem strange, and what they mean?
The contact form is setup to return mail to m76@gmail.com and forwards to m76@twrlds.com (names changed here for privacy)

Return-path: <m76+caf_=m76=twrlds.com@gmail.com>
Envelope-to: m76@twrlds.com
Delivery-date: Tue, 01 Jul 2008 01:07:07 -0700
Received: from rv-out-0708.google.com ([209.85.198.243])
by chico.spry.com with esmtp (Exim 4.69)
(envelope-from <m76+caf_=m76=twrlds.com@gmail.com>)
id 1KBe9p-0007OM-QM
for m76@wrlds.com; Wed, 25 Jun 2008 16:12:09 -0700

Also--
I have been starting to get a lot of spam messages through this form, (lists of 1000 domain links in the body). It there a way a program cvan be written to do this from outside the ISP, since there is no email exposed, and it is just an html form that sends the email? Or is a person actually inputting this info? The domain for the posts are all from the same place, (somewhere in china), so I am assuming it is sent from a proxy server.

Also--
I received today, an email from someone I blocked on the account-level, through a rule in my admin software, (it is provided by my ISP, and is linux based). I asked my ISP, who then told me it was because I had not set up spam assasin. But I had checked and tested, and it blocked without having this set up. I even tried it again today, and it blocked fine. So how was someone able to get an email to me, who is blocked? (They have been harassing me). Does this mean it is happening from the ISP? Do I need to change ISPs?

Thanks very much,

Edit: Moved topic from AntiVirus, Firewall and Privacy Products and Protection Methods to the more appropriate forum. ~ Animal