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Forum Moderators: buckworks
Follow basic guidelines and start experimenting with places like hotmail / yahoo / gmail and a couple of popular ISPs and you'll quickly figure out what is working.
Remember to keep a test mailing list on whatever program you use and send every mail to the test list first, incase spam filters have changed or your content has changed -- causing it to be trapped as spam.
Knowing this, if I were writing a spam filter I'd be more likely to trust those applications that are well-known and cost a few bucks. But not without a scan of their headers and content for sure. ;)
That being said, my suggestion would be to investigate SendStudio or ConstantContact