“Email marketers should consider sending approximately the same number of emails each week or month instead of inconsistent sending sprees. This means marketers may want to plan ahead before big events that might cause email volume to fluctuate, such as corporate events or consumer holidays.”
Email service providers may flag your emails if you suddenly start sending a large number of emails at irregular intervals. According to Media Post, the deliverability of your emails will increase if you are consistently sending the same number of emails throughout the week or month.