What about the subject line?

Are there good subject lines and if so, how can you ensure yours are doing the work? With a good subject line, you can get 10-20% higher open rate so it is worth spending some time considering. As usual in email marketing, there is no solution that fits all, but we have although learned some things about subject lines over the years. Here are some things to consider.

Test!

Get to know your recipients by performing structured AB(CD) tests. No recommendations in the world can replace their input which you’ll get through testing and monitoring the statistics. Remember to include other variables like timing, recipient segments and list size into account, too.
Read more about AB(CD) testing.

Find a good tone, but don’t repeat yourself

Depending on your target audience and purpose of the email a good subject can be descriptive, specific or inspiring, sometimes it can even be good to meet the so-called effective FOMO (fear of missing out). Through testing, you see what works best for your audience – but don’t get caught in using only one kind of subject line. Test different ways to engage your audience, they will appreciate the variety.
But hey! Stay away from things that sounds “spammy” such as “SALE !!!” and inappropriate words, of course.

Make sure the subject line looks good, no matter where the recipient opens the email

The subject line should be brief and to awake curiosity. Don’t exceed 49 characters including spaces and your whole subject line will be visible, even in mobile email clients. Note that special characters (such as -,%, ©) can be flagged as spam, and unfortunately, it happens even with emojis sometimes, ☹.
In addition to the subject line, you should ensure that your sender and reply address match.