Is there any sort of industry standard on how often is too much for emailing a group of emails? I am not refering to weekly emails that go out on the same day and time but rather impromptu emails letting people know of an event.
This is the kind of question that probably has 1,000 correct answers - it really depends on the expectations of the subscribers to your list. Are you telling them up front how often you will be emailing them? If the site says "we'll remind you a month before, and a week before", for example, the expectation has been set in their minds.