As often as you can, without getting annoying. How’s that for a vague answer? But it’s true – you want to send frequent emails, but not so frequent that people start unsubscribing or worse, marking them as spam. Where’s the happy medium? Unfortunately, it’s different for each business. For some, once a month is plenty, while for others, daily emails are just fine. Again, it’s a matter of experimentation and testing to see what your particular audience responds best to.