How to Generate Email Subject Lines That Respond (2024)

It does not matter how good your email copy is. If the subject line fails to catch the reader’s attention and tempt them to take the next step, which is opening your emails, your efforts will be thrown into the water.

So, how do you write compelling email subject lines so that your email campaigns will get higher open rates and increase the email inbox rates?

In fact, there are several ways:

  1. Use proven email subject lines — This could be an email swipe file you made yourself or got from someone. However, the downside is that you must ensure the email body text matches the email headline.
  2. A/B test email subject lines — Most email marketing tools like GetResponse, ConvertKit, and Aweber allow A/B testing subject lines and use the winning one. However, the downside is that it will take time to get a reasonable result.
  3. Use AI email subject line generator — With the birth of AI-based tools, online marketing as a whole got refreshed and eased lots of aspects and opened new ways how you conduct marketing and advertising. Now, there are several email subject line generators that make it easier to make decisions based on statistics.

In fact, when I am starting to send an email broadcast, first, I write the email body. Why? Because that eases my mind to flow the content and makes the message more enticing gets the reader to act.

Though, what happens when you write the subject line first and then the email body is that it makes it harder to write a compelling message that resonates subject line.

So, in this article, I will share how to generate email subject lines to boost open rates based on the message.


How to Generate Email Subject Lines to Increase Open Rates

Please note that it does not matter how good the email subject is. You will not get attempted results if your email marketing tool does not deliver emails to subscribers’ inboxes. So, make sure to use a good tool like GetResponse (review), Gist, ConvertKit, or even Actionetics from Clickfunnels.

My favorite email subject line generator is Anyword AI. Anyword is an AI copywriting tool that lets you generate not only copies for your marketing campaigns but also provide predicted insights.

Find out for which audience the message is tailored and the overall email subject quality score.

The specialty of Anyword is that the team behind it has spent over $250 million on paid ads before, and the data is integrated with their own built predictive performance algorithm. Check this Anyword review to find out more details.

First of all, sign up on Anyword over here and verify your email address. After that, click on the ‘Create project‘ button. Now you will see the options below.


Click on the Email box to generate subject lines for both marketing and direct emails.

I will start generating subject lines for this email by Neil Patel.


Next, you will see a page like in the screenshot below.

  1. Enter the name of the project
  2. Enter the email body text
  3. Select the industry or topic

You will have two options:

  1. Generate with AI – If you want to create new email subject lines, this option is the one you’d use
  2. Improve with AI – Suppose you already have a subject line for a newsletter campaign but want to improve it. Improving with AI is the ideal option for you if that is the case.

Generate New Subject Lines for Emails

Enter a keyword (up to 3 words) and click on the “Generate” button. Here are some email subject lines generated by Anyword AI. Hover over the performance score to see more details.


You can find:

  1. Predicted performance for each demographic sector
  2. Which gender is more responsive to the generated email subject line?
  3. Is it safe to use? Ex: Will it contain any spam-triggering words

Improve Existing Email Subject Line and Generate Variations

Click on the “Improve with AI” tab and enter the original subject line.


According to Anyword, the original email subject line is poor and has only a 16% performance score.


There will be two options to generate new variations based on the original email headline.

  1. Strict — Keep the original meaning. Perfect if you are generating email subject lines for promotions
  2. Relaxed — Let Anyword generate more high-performing subjects for emails. Excellent if you write emails in a personal or conversational tone that you want to capture subscribers’ attention.

Also, you’d see that Anyword allows you to fine-tune the Demographic filters when using the ‘Improve with AI’ option. For instance, if most of your email subscribers are males and above 25 years of age, to get hyper-targeted email subject lines for the particular audience segment, choose those demographic filters.

Email subjects with the original meaning


Email subjects with higher engagement rates


Generate email subject lines based on the gender and age

Specify the gender and age on the left panel and click the Generate button.


The subject title for the email, “5 Hacks That Will Make Your Business More Successful,” has a whopping 80% predictive score, and it is supposed to perform well with males within the 25 – 65 age range.


Generate responsive email subject lines

Here is an email by Ben Kropkof of The Email AgencyTM


Hey Chamal,

SMS marketing is becoming a huge trend for Ecomm businesses in 2021.

This year alone, I’ve probably signed up for a couple dozen SMS lists to get deals at stores I shop at.

I’m curious to hear your thoughts on this new type of marketing…

Have you tried SMS for your business?

If not, are you thinking about giving it a go in Q4?

Or does the whole idea of texting your customers turn you off…

Reply to this email and let me know!

Have a great weekend,


Let’s find out if Ben could have gotten more replies by optimizing the email subject line!

According to Anyword, the original subject line is okay, although 13 – 17 aged people have a majority of predicted engagement scores.


Email subject lines like “What do you think about texting?” and “How would you feel about SMS messages?” not only have got higher predicted performance scores but also encourage people to share their views on SMS marketing which is exactly what the email copy encourages people to do.

How to use generated email subject lines in your email marketing

Although generated subject lines for email have got higher predicted performance scores, it is not 100% guaranteed that those will resonate likely with your subscribers.

Copy two or more subject lines and conduct an email subject line A/B test. Analyze the performance based on real, tangible results like sales, link clicks, and replies, not just open rates.

For instance, if you are selling something (ex: promotional email), optimize the email subject line to coordinate with your sales funnel. Link rotator tools like ClickMagick and affiliate link tracking tools like RedTrack allow tracking conversations on simple to complex funnels.

Also, if you are in a business like Solo Advertising and want to maximize clicks to make more money selling email traffic, aim to get users to click on the email’s CTA link(s). Check out these internet marketing email swipes for inspiration.

Conclusion on Generating Responsive Email Subject Lines

Improving the subject lines in emails alone can boost all other metrics like revenue per subscriber per month, Lifetime customer value, and even inbox rates.

One of the easiest and most efficient ways to get irresistible email subject lines is by generating them using a powerful tool like Anyword.

This tutorial taught you how to use Anyword AI copywriting tool to optimize your email subject lines.

So, which methods are you currently using to brainstorm email subject line ideas to boost email open rates?

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