A legitimate message mistakenly rejected or filtered as spam, either by an ISP or a recipient’s anti-spam program. The more stringent an anti-spam program, the higher the false-positive rate.

Building an Opt-In List, Building Relationships
If you aim for success, you must do everything within your means to achieve that. You just donÃt go on sitting there in your house complaining about not getting as much profit as you expect.