Should email subject letter be capitalized?

Jan. 28, 2019, 1:25 p.m.

1 Answer

Feb. 25, 2019, 9:40 a.m.

Many marketers and copywriters who deal with e-mail marketing on a daily basis face this challenge: what title give to the e-mail so that it is not omitted from the recipients. Often, the idea is to capitalize every letter of the title so it will be more visible. However, does this have an impact on the open rate, and maybe only annoys your audience are even less likely to open such a message? Or maybe it's better capitalizing only the first letters of words? Let's find out.

The decision seems like an aesthetic one, so it be should totally based on your own preferences, style and of course, the context.  Capitalizing the first letter of the subject line gives the title more professional appearance. However, for long subject lines, this solution may be a bit overwhelming. Moreover, capitalizing every letter looks like shouting.
It works on very special occasions such as promotions or big discounts, but in everyday newsletters will be very exhausting for your recipients. If every message is THAT important, then nothing is special.

To be honest, the only proper way to determine the best approach is A/B testing on your particular audience. Inntopia made such testings which proved… not much. They have analyzed their emails open rate comparing messages with titles including each word capitalized and only the first one as well. The results weren’t much different. When just the first letter was capitalized, email open rates were a half percentage point higher than their more title-like counterparts. Instead of about 16.2% open rates, they gained 16.7%.

So, capitalize or not capitalize? It really depends on you and the style you prefer. The best option is to test it on your recipients and analyze yourself what option gets the higher open rate. One thing you should remember, that whatever option you choose, you should be consistent about it. It’s part of your brand’s signature style, so don’t change it too often.