At first, you might be nervous about mailing to your list because you're not sure how many messages you should send and how often. Unfortunately, there is not one correct answer to this question. The answer depends on your niche, the relationship you have with your members, and what kind of information you share.
If your messages offer a lot of value, people will probably want to receive them more often. If your list messages are more focused on making sales, people may expect them (and want them) less often.
Still, the balance is individual, so you should test what is best for you. A good autoresponder will show you the number of people who click on your message when you send it. If the number stays high with more frequent messages, your unsubscribe rate doesn't increase, and sales tend to remain high, then your list may want to be contacted more frequently.
What some marketers suggest is having one autoresponder message scheduled per week, with perhaps a broadcast message in between if you need to have a special mailing. Yes, at times the messages might land on the same day to certain readers, but that's no reason to avoid sending broadcast mailings to your follow-up message recipients.