You have a list of subscribers to your newsletter and you regularly send emails to send promotional offers to your customers, or simply news. Only, you realize that the opening rate of your emails is not very high. You have already researched many solutions on the internet, but today you want to focus on the subject of the email . Wondering what size should be the subject of the email . And that’s a really good question, which we’ll answer in this article. Here are some things to consider when choosing the right size for your email subject lines.