Increase email open rates with better subject lines

1. Consider the subject line while creating your email — not at the end.

Do not wait until the email is designed, written, coded, and approved before thinking about subject line ideas. Don’t treat subject line writing as an afterthought, waiting until the end and spending only a few minutes coming up with ideas. Since the subject line is so important, brainstorming and revising should be part of the email creation process from the beginning.

Keep an ongoing, in-progress, always-changing list of ideas. When you are ready to blast out your email, spend time reviewing all the ideas that you have come up with, and then choose the ones that you think will be best at getting recipients to open the email.

2. Come up with multiple subject line ideas … and test them.

We provide our clients multiple options for a subject line not only to give them a choice, but so they can actually test subject lines to see what works best. Creatives and marketers often think they “know” what will work or not, but it’s far better to test different options, and learn from that testing.

Make sure subject line tests are accurate in that the A/B testing is fair and equal between two options: sending to the same list with the exact same content at the same time of the day. Depending on the size of your list, you could try 3, 4, or 5 options, if possible. Be sure you have solid tracking in place so you can check open rates, clicks, and conversions for each option. Document the results and keep that information handy — and share the results with the creative team so it can refine the design and content of subsequent emails.

3. Be clear and direct. Don’t be cryptic.

In your subject line, be clear about what’s in the email. The subject line’s job is to describe what’s inside and why the recipient should want to read the entire email. That may be a tall order — and will take some work — but you will get a better open rate with a well-crafted, descriptive subject line than with something cryptic like “Want to save your business?” or “Amazing tips that you won’t believe.”

Take the mystery out of what’s inside your email. Be witty; be funny — if the situation encourages that tone. But just make sure the wording is clear, direct, and accurate.

4. Write subject lines in tandem with the From line and Preview pane copy.

When recipients get your email, they can read the “From” line, the subject line, and depending on which email app and settings they use, they will also see some brief copy in the Preview pane. This means you actually have three places to give your readers information about the email before they open it.

If the From line includes your organization’s name, then you don’t have to include the name again in the subject line. And, if you write preview copy that supports the subject line in a logical, compelling way, you can give readers enough information to want to read the full email.

5. Keep subject lines short, but don’t kill yourself over it.

The rule of thumb is to keep subject lines to 50 characters or less. That comes from the idea that anything longer than that will be cut off, especially on a smartphone. However, that’s not entirely true — it all depends on a recipient’s email app settings.

It does make sense to keep subject lines as short as possible, but it’s more important to clearly state what’s inside the email and provide a reason for the recipient to read further. If you need a few more characters to be descriptive and compelling, then use them.

6. Avoid spam filters as well as users’ personal filters.

To avoid having your email get stuck in spam filters, you should avoid words that may tend to trigger spam filters, such as “Free,” “Guarantee,” “Amazing,” “Cash,” and “Earn.” (Search online for “Words that trigger spam filters” to see several lists, though there’s not one definitive list.) Also avoid using ALL CAPS and extra exclamation and question marks that might trigger spam filters, OK!!??

Besides the spam filter possibly blocking your email from getting to inboxes, people use their own judgment on how spammy your email appears before deciding to read it. Each person has their own “filter,” ready to reject your email for any number of reasons — overhyped/too-good-to-be true offer, information is not relevant to them, they don’t know who you are, etc. Make sure your email is targeted to your audience, and the subject line and preview copy are clear and direct.

7. Create a sense of urgency without getting spammy.

Without using words that might trigger a spam filter — such as “Act Now!” or “Limited-time offer” — it’s often good to include some mention that the offer is time-sensitive. The best way to do that is to mention an exact expiration date, such as “Webinar on B2B lead gen ideas — Register by March 1.” You state what the offer is, give a date, and create a sense of urgency.

8. Subject line for an e-newsletter — mention the contents.

For e-newsletters, it’s fine to include the name of the e-newsletter (hopefully, it’s short) and the date (or the month). But don’t end there, since a user may not recognize that it’s a new email nor have any reason to open it up. Include copy about the lead article or a description of the types of content in the newsletter, something like, “April Gazette — Mobile app for writers, new tips, and more.”