Hi Sausagestore! You could certainly sign up to another ISP just for your bulk emailing.
We do not recommend any ISP in particular, however, you should sign up with an ISP or mail host who offers full SMTP services (
www.ispfinder.com or
www.thelist.com are good sources to locate one ).
As a desktop bulk email provider (
GroupMail), we do not recommend the use of Free ISPs or Mail Service Providers if you are serious about legitimate bulk emailing. Also, you should contact the ISP or Mail Service Provider you intend to use and verify with them that they will allow bulk mailing through their servers, in order to avoid being shut down without warning. Work with your ISP, not against them.
If you fulfill permission marketing requirements (opt-in and opt-out, etc.) and work within your ISPs sending policy; you should have no problems.
You spam when you send unsolicited commercial email, regardless of how many messages you are sending. The fact that you are sending in bulk does not mean that you are a spammer. I receive the New York Times email each day. I'm sure that there are hundreds of thousands of people on their mailing list - but they are not spammers. They use permission-based subscriptions and have built a nice list over time.
Here are a couple of articles I wrote that you might find useful
Permission Email: 5 Key Requirements
Email Deliverability: 10 Steps to Romance ISP Filters
All the best
Tom