What is the perfect length of an email campaign? #WhiteboardWeekly

This question has popped up quite a bit when talking to businesses over the past couple of weeks. How long should my email campaigns be? How much content should I include? So it seemed a perfect subject for this week's #WhiteboardWeekly.

We'd love to hear your questions for future episodes of #WhiteboardWeekly, all you have to do to get your question answered is tweet us: @astonishemail.