
Here is all the research around email subject lines
Dec 10, 2022
We tried to collate all the research around email subject lines and come up with a bunch of understandings and guidelines based on that.
Here is what we found. Credits are given where needed.
Remember the whole purpose of this document is to increase open rates.
Importance of sender names
Turns out its not just subject lines but also the sender name that influences people to open their emails. According to research done by Superoffice 69% of subscribers say they open emails by looking at the sender name and trusting them and 47% open based on an enticing subject line.

Pinpointe marketing conducted a research that by using a specific person's name, you can increase the open rates by as much as 35% instead of a company name!
Subject line best practices
Retention Science found that the ideal length of subject lines is 8 words.

Addressing the user by name in the subject line can increase your open rates as much as 20%.
If you add something quirky like movie titles and song lyrics, your open rates increase.
Including the word video in your subject line can increase your open rates by 6%.
Dan Zarella found that the words "secrets", "e-sales" and "awesome" were the most clicked on.
"confirm", "features" and "upgrade" were the ones that were most reported as spam. Its also best to avoid including question marks or hashtags in your subject line.
Preview Text best practices
Along with the sender name and the subject line, another piece of content that influences open rates is the preview text.
Here is a bunch of spam in my inbox that has bad previews text

Here are the best practices...
Don't leave it empty
Don't let it show your address, or "view it in your browser"
Done repeat the headline
Extend the headline and add value
If you are looking for a way to send emails at 1/100th the cost of MailChimp, we have created a simple tool that send your emails through Amazon SES. You canuse it at just $20/Month and send emails at just $1 per 10k emails as against Mailchimp's $200 per 10k emails.