You can calculate the average cost of an email marketing campaign by taking the following into consideration: The cost of your email marketing software. How often you send email marketing campaigns. The cost of employee/agency time spent to plan, design, and send the campaign. The cost of deliverability – if you have a high bounce rate or a high risk of spam, you might have to pay more to ensure your emails make it to the right recipients. The easiest way to determine the average cost of an email campaign is to use an email cost calculator.