Tips for writing ‘engaging subject lines’

Email subject line is the first thing that signals your recipients if they really need to open the email in question. A subject line could get your prospects excited to read your email or irk them enough to mark it spam

Best Practices

Keep it crisp and clear: Studies suggest that people get over 100 emails a day on average. That is a big bunch of emails so it is obvious that any email not having good subject lines is likely to be ignored.

People get irritated at emails (and at the senders) that waste their valuable time. Let them know what your email offers them and why they should open it. This is especially applicable if you have an unique value proposition for them. Try and see if you can call out this value add on the subject line itself. 

For example, ‘Our industry-first verification solution’ could be good enough to get someone in the relevant space to open your email.

Don’t trick your audience with an attractive subject line and then underdeliver with the actual offer. 

For example, a subject line promising “50% off” creates certain expectations for your prospects. Imagine if you can only offer 50% off for a select range — your prospects aren’t going to trust you the next time you send a marketing promotion.

Some examples of winning email subject lines: 

  • You’re missing out on favourable deals
  • Tonight only: Get the best discount 
  • {!Target company name} and {!your company name}
  • Hi from {!your name}
  • Hi {!Recipient name}
  • Our industry-first {!solution/service name}
  • Quick question

Personalize: Try and make your subject line easy to understand, highly relevant, timely and tailored to your prospects to help you stand out from the other emails. Research and use the information you know about them such as Birthday, recent news or achievements etc.. to give more personalization.

Some examples of personalized email subject lines:

  • Hi Mary, Happy Birthday
  • Congrats on the new funding round
  • Read the article, {!Article name} 

Consistency: To make sure your subject line aligns with the rest of your email message it’s good to write your subject line only after you’ve developed the email copy. Your email subject line acts as your title and will be the gist of what your email copy details.. Extract keywords from your copy or headline into the subject line to give your key message more visibility.  

Always keep it short: Space is limited in subject lines. If the entire subject should be viewable on mobile devices, the limit is 30-40 characters. Emojis have become popular in recent days because they quickly express a lot in one character. They can definitely help you improve the open rate.

What to Avoid

Spam: One of best ways to avoid SPAM filters/firewall monitors or bots is by carefully choosing the words you use in your email’s subject line. Trigger words can cause problems and increase the chances of your email getting caught in a SPAM trap.

Some words to avoid:




You Won

Act Now

Order Now


A/B testing

Testing your subject lines with A/B or split test gives you more confidence before sending your email to your entire prospects. The most important metric for gauging results is open rate. Feel free to check unsubscribes rate or click through rates to determine how your email will possibly perform. If a prospect is still not engaging with you even after you have sent 10+ emails , it’s time to consider not emailing them again at least for a quarter.


Every business is different and unique so there’s no one recommendation for writing email subject lines.  Be creative and always test to figure out what works best in driving opens, clicks and conversions so you can reach your business objectives.