Also, I see Choicemail is permission based anti-spam .... this sort of technique, known as greylisting is a waste of time.
It is a totally unnecessary type of anti-spam technique in the 21st Century and only causes frustration to sender and recipient if you forget to unblock someone's first email or miss the notification from the software.
Again, not poking at Choicemail here, just at the overall concept of greylisting.