Subject Lines

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47% of people open emails based on the subject line alone, according to research done by Business2Community. Your email subject lines can mean the difference between an email campaign being a successful conversation starter or being a total flop and getting flagged as spam.

This is your opportunity to introduce yourself and your intention, while also addressing your customer’s goals and pain points.

Why are subject lines important?

Trillions of emails are sent each day. Subject lines are a way to stand out from the crowd and grasp your client’s attention, while also helping filters to weed out spam emails.

Having a good subject line that avoids using spam triggers not only helps your email get past the spam filters and boosts your inboxing rate, it can also boost your open rates.

With the introduction of more intelligent inboxes like Gmail’s Priority Inbox, the recipient is highlighting which emails are more important than others by engaging with them. The more they open emails from a specific sender, the higher those emails rank in their inboxes.

Email subject lines are the call-to-action that really drives results. Without strong subject lines, even the best emails may go unread.

How do subject lines affect email deliverability?

There are hundreds of factors that go into reaching the inbox.

But let’s talk about subject line spam filters.

Spam filters have a list of keywords, phrases, and text styling triggers that scoop up bad emails and either send them to the spam or reject them completely causing your inbox rate to tank.

Some of the worst offenders on this list include:

  • !!!
  • $$$
  • 100% free
  • Act now!
  • FREE

In a study done by Oracle in early 2018, results show that emails with spammy words such as “free” and “money” caused a significant drop in the performance of Apparel and Pet Supplies.

Here is a list of spammy words you should avoid using in your subject line so you are less likely to be flagged as spam.

What does the MailGenius email test tool cover with regards to subject lines?

  • Spammy word check

Caveats, things to watch out for:

  • Don’t send out misleading subject lines. Not only does it break the trust between you and your audience, it also violates American anti-spam laws.The CAN-SPAM regulations set out the rules for email marketing and deceptive headlines are a big no-no. For every single email sent breaking these rules, the sender is subject to a penalty of up to $41,484. Using misleading subject lines also hurts your brand image, annoys subscribers and can have a negative impact on your email’s reputation when they’re flagged as spam.
  • Don’t use spammy words such as “free” and “money” in your subject line.
  • Most mail servers show a preview of the email right under the subject line. Preview text should not match the subject line. Differentiate them to have them help each other out.
  • Don’t capitalize every word. Your subject line is not a title of a book. You have to use subject lines the same way as you use emails- as conversation starters.

MailGenius Tips and Tricks

  1. Keep it ASAP (As Short As Possible): Today’s business professional is always on a time crunch. If they can’t read and act on your subject line in a matter of seconds, they probably won’t be interested in reading your email. Since 46% of emails are opened on mobile, try to keep your subject line under 50 characters (or 5 words) to ensure that they can see the intent of your message at a glance.
  2. Personalize your subject lines: Doesn’t it feel nice when you get an email that’s personally tailored to you? Personalized emails are 26% more likely to be opened, according to Campaign Monitor. Consider adding personalized tags such {first_name} in your subject line to attract with your reader.

Additional Resources

  1. 20 Hacks for Improving Your Email Subject Lines- CampaignMonitor
  2. The Cost of Free: Subject Lines and Email Deliverability- Oracle
  3. Understanding the Impact of Open Rates and Subject Lines- OutboundEngine
  4. Email deliverability: 10 things landing your emails in the SPAM folder- Rebrandly
  5. How Long Should an Email Subject Line Be?- AWeber