We use CC and have had good results, the first time I sent an email which happened to have 5,000 emails I was only allowed 1 spam report per 1,000 emails and I got 8 which shut me down. These were my on-line customers, not emails I collected. Over the last 18 months I can send a 5K email and get no spam reports or I can send 300 emails and get 2 or more spam reports and CC will suspend your account until you call in and get the talk. It has worked for us, remove any googlecheckout.com emails and all .gov, .fbi, .edu if you sell them as they are most likely blocking the service anyway. Any third party checkout services need to be removed, the reason is that buyer has no way to easily remove his email as his account is with the third party and not your site. Overall CC has worked for us and is worth the $50 a month.