The answer to this question depends on a number of factors, such as the nature of your business, the type of email campaigns you send, and your goals for each campaign. However, as a general guideline, it's generally advisable to email your subscribers at least once per month. This frequency will help keep your brand top-of-mind, without bombarding your subscribers with too many emails. Of course, if you have important news or announcements that need to go out more frequently, you can always adjust your email cadence accordingly.