You thought you crafted the perfect email campaign. It was targeted to your audience. The copy was short and snappy. The graphics you included were nice and clean.

Then you track your open rates and you’re incredibly disappointed. Not as many people were as receptive to the email as you thought they’d be.

What happened?

Sometimes, as marketers, we get so caught up in what we think looks great that we forget to think about what our audience would like. Thus, we launch what seems like a winning email campaign only for it to fail.

That’s why, before you ever hit send, you have to make sure you do email A/B testing. Also, known as split testing, A/B testing is a crucial part of a marketer’s job. With this testing, you take two variants, A and B. Then you test among your audience or similar audiences to gauge which one is preferable.

An A/B testing campaign can be the difference between awesome open rates and abysmal ones. That’s why it’s so important you make this testing a part of every email you send.

If you’re unfamiliar with A/B testing but want to start, we recommend you begin with this article. In it, we’ll share 11 email testing ideas you can use for your own campaigns. Each of them should increase your open rates.

  1. Link Count Testing

How many links are in your emails? Is it just one or two or do you have way more than that, like five or six?

While we recommend you test this, generally, the fewer links you have, the better. There are two reasons for this.

The first is a psychological one that employs what’s known as the paradox of choice. Perhaps you’ve heard of the famous jam study. If not, here’s a recap: two groups of people were at a supermarket. Both got a selection of jams to pick from, one with six jams and the other with 24 flavors.

While people liked the table with more varieties of jam, they didn’t buy nearly as much jam as those did with fewer options. That’s because the more choices we get, the harder it becomes to pick something out. In the end, most people will just walk out empty-handed.

The same thing applies to your links. The more you have, the tougher it becomes for the email reader to decide which ones to click on. In the end, they may not click on any of them.

The second reason we recommend you cut down on links is aesthetic but still viable. It’s simply because too many links look spammy. Your email could get stuck in the spam filter instead of the recipient’s inbox.

  1. Email Send Day/Time Testing

As we’ve written about a few times on this blog, Tuesday, Wednesday, and Thursday are your best days to send emails. The most ideal times to send email are early in the morning, midafternoon, and/or later in the evening.

best time to send emails

Image courtesy of CoSchedule

Okay, so if that’s all so concrete, then why bother with email marketing testing? Well, because those times and days can fluctuate slightly depending on your audience.

Even once you think you know the best days and times your audience is most receptive to your emails, it could change. This is something that will always be in flux, and you have to be prepared accordingly.

At least monthly, you should A/B test when you send your emails. Then, accommodate the latest preferences of your audience.

  1. Email CTA Testing

Ah, the call to action. It’s so necessary, but is it working for your company?

Your email CTA can appear in several formats. Perhaps it’s a line of text at the end of your emails. Maybe you’re a bigger fan of the CTA button, so you park it front and center in your email.

There’s proven research that shows the CTA button is more effective than a link in emails. According to data from Campaign Monitor, it’s possible to see a 28-percent boost in your click-through rate with a button.

That might be the first thing you test then, whether a text CTA or a button performs better for your audience.

Once you make that decision, you’re not done yet. You should also test for the following:

  • The amount of whitespace your email has, which can either obscure your CTA button or let it stand out
  • The color of your CTA button as well as the other colors in your email, including the background; these should be two separate tests
  • The design of the button, like whether you include effects like shadows or not
  • The size of the button
  • The placement of the button
  • The CTA button copy
  1. Anchor Text Testing

Are you using anchor text in your emails? If not, you’re missing out on a great way to pique the interest of your audience.

What exactly is anchor text, anyway? This is a hyperlinked copy that often ends in an ellipsis. It’s a preview of what’s to come that’s meant to tantalize the audience and draw out their natural sense of curiosity.

Here’s an image that showcases how anchor text can play to several emotions.


Image courtesy of Yesware

The first option you have to is to get your audience curious. If this is the approach you take, then the accomplishment you highlight should be something they themselves would want to do. Your company also has to be well-known enough that if mentioned by name alone, people know who you are. Make sure you don’t give the whole secret away in your anchor text.

You can also invoke empathy in your audience, but you’d have to know their pain points to do this. Maybe your audience is having a tough time converting leads or getting anyone to read their blog. By showing you’ve had the same problems and were able to overcome them, you display your empathy.

Finally, you can get your audience scared by making them feel like they’re missing out on something awesome. That’s what FOMO is all about, after all.

No matter which of the emotions you go for in your anchor text (and maybe it’s another emotion entirely), remember this is just a preview. Once the reader clicks the link, they’ll get the whole story.

  1. Personalization Testing

You know you should personalize your emails, but how much personalization is enough? Only A/B testing can answer that question.

Here’s a great example of a travel company. You can see two personalized emails they tested side by side.

A/B testing

Image courtesy of Vision6

In the first version of the email, it isn’t super personalized. Yes, it says “featured hotels just for you,” but that’s about as far as it goes. On the other side of the email are all the exotic locations a customer might want to travel to. It’s a good email, but is it great?

Not as great as the second email. This one has the name of the email recipient outlined in the sand. Their name is also in the first line of the body beneath the image.

How excited would you be to see your name traced in the sand? Very, right? That alone is going to make you want to read through the email.

Get creative with your personalization. Whether you do something like this travel company or you make your audience feel unique in some other way, A/B test it.

  1. Tone Testing

How do you write your emails?

Perhaps you take on a more informal tone, such as the voice of this blog post. It’s relaxed yet informative and feels like talking to a friend rather than a colleague. You’re reaching out to your email audience on a more personal level.

Maybe you prefer the formal approach. The writing is more buttoned-up and may include jargon and terms that only those in your niche would understand.

Both are appropriate in some instances and industries. Also, your tone might vary depending on which audience segment you’re trying to reach. You might write in a more relaxed tone with your established customers and more formally with your new ones. The opposite could also be true.

The best way to know what your audience will like best is through split testing. Prepare two versions of the same email, one with an informal tone and the other written more formally. Then see which one gets the highest open rate.

Testing for email tone is not a one-and-done thing. You’ll have to keep repeating the test when sending out major emails to new and established customers alike.

  1. Content-Length Testing

No one likes slogging through a novel of an email. Going in the opposite direction can be risky too since brevity can also be vague if you’re not careful.

Your open rates could be suffering because your emails are simply too long. As you guessed, the best way to know is through A/B testing. We recommend testing at least three versions of an email. One should be the long one you prepared with love and time. The other should be a mid-length version that’s shorter but not too short. Finally, try to condense your message into the least amount of words possible.

Now test all three emails to see which gets the highest open rates. We’d bet it’s probably the mid-length one. That’s not to say that longer emails never have their place. In a newsletter email, for example, your audience expects a longer, meatier message.

Short emails are also appropriate in some instances. If you’re sending a reminder about an upcoming event or webinar, this wouldn’t be very long.

Are you having a hard time cutting your emails down to size? You could always try adding some images to break up long blocks of text. 2018 data from HubSpot found that many consumers (65 percent) liked seeing images in emails more than they did text.

Have you written about the subject before in a blog post? Then link to that rather than devoting paragraphs to the same topic in your email. This lets the audience choose if they want to do further reading on the subject or not. Just remember not to add too many links.

  1. Link Text Length Testing

Speaking of links, there are so many ways you can format them. For instance, let’s say we’re linking to our EngageBay homepage. We could just say “check out EngageBay for all your marketing needs” and link to the name of the company. Alternately, we could do something like this: “if you need an all-in-one sales and marketing software…”

When you add hyperlinks to your email, how should you do it? How many words should be included in the links? This is something else you’ll have to test for yourself.

Most marketers agree that 12 words are the max amount. Here’s a MailChimp illustration that shows that data in more depth.

words per URL

Image courtesy of MailChimp

It appears the more words you cram into your email links, the lower and lower the email open rate is.

  1. Greeting Testing

Did you know the very opening words of your email can be a big determinant of your campaign’s open rate success? It’s true.

Whether you say “hello,” “howdy,” or “good morning” does matter. How important this all is to your audience is up to you to find out through A/B testing.

Like the body of the email, the tone of your email greeting will vary. If this is a new customer and you’re keeping a somewhat formal tone, you might write “welcome” as your greeter. For older, established customers, starting your message with a “hey there” is perfectly appropriate.

What seems to matter most in terms of open rates is greeting personalization. Instead of “Hello,” try “Hello, [name].” Here are some good examples to get you started:

hearts and tails

Image courtesy of Constant Contact

My Giftlist

Image courtesy of Oracle


Image courtesy of Buffer

  1. Subject Line Copy Testing

You had to know this was coming. One of the most important parts of any email campaign is sending messages with stellar subject lines. This is the first impression you make on your email recipient, after all. It has to be a good one.

There are lots of ways to craft a fantastic subject line. Personalization is always good. Stats and figures can pique interest. Discounts and deals get most people clicking. Your company might even support the liberal use of emojis in subject lines.

Emojis by subject line

Image courtesy of MailChimp

Whatever works for you, you have to know for certain. An A/B test will truly come in handy here.

Your subject line, like your anchor text, can connect with your audience on an emotional level. Once again, you might try to come across as empathetic. You can also foster that sense of FOMO by sending an email about a deal that’s only good for today or a sale that’ll last 12 hours more.

You can try to get your audience curious by writing a subject line much like you would your anchor text. You make a partial statement, ending it with an ellipsis. By telling only part of the story, you hopefully intrigue your reader enough that they want to click, open the email, and see how the ending goes.

  1. Subject Line Length Testing

Okay, so you’re confident the content of your subject line will appeal to your audience. You A/B tested it and everything. You’re all ready to send the email, right? Not so fast.

You should also test for the length of your subject line before you launch your campaign. Exceeding 50 characters is no good, as there’s a chance the audience member might see a cut-off version of your subject line. This depends on the device they’re using, of course.

On smartphones, your audience is more likely to see the crudely chopped subject line. If they have a Galaxy S4 device and use it in portrait mode, Yesware says the email will be cut at just 33 characters. If they’re an iPhone owner who use their phone in portrait mode, they get 35 characters, maybe 38. By flipping their phone to landscape mode, it’s 80 characters, but who does that?

Five words is the sweet spot. This should fit the character count requirement so that even if your audience is on their phone and holding it in portrait mode, they should see the whole subject line.


A/B testing in email marketing is a crucial part of your campaign’s success. It will influence email open rates and click-through rates as well. By starting an A/B testing campaign, you can be sure all elements of that campaign resonate with your audience.

Nothing is too small to split test. From the placement of your CTA button to which time to send an email, it’s all worth it. Some elements of your campaign will have to be tested regularly and others just once or twice.

Knowing your audience allows you to create stellar, winning campaigns. A/B testing ensures all parts of your campaign are tailored to their interests and pain points, winning you loyal, buying customers.