Getting your B2B marketing email into your customers’ inboxes is only half the battle. Once it’s there, you have to convince them that it’s worth their while to open it, read it, and click on your links. Whether they open your email or not usually has a lot to do with your subject line. Here are a few best practices for creating B2B email subject lines that stand out and attract clicks from your customers:

• Avoid words that trigger spam filters. Many spam filters are triggered by specific words and phrases as well as email frequency and email source. For instance, “Free Ebook!!!” seems like a good, compelling subject line, but “free” is a trigger word for many spam filters, so your customers might never see this great offer. Other words and phrases that frequently trigger spam folders? “Click here,” “Open me,” and “Help.” And while subject lines in all caps or with multiple exclamation marks might not trigger automatic spam filters, using them is a surefire way to get people to manually mark your emails as spam. If you try too hard to attract attention with the wording, capitalization or punctuation of your subject lines, real people and email filters alike will assume that what you have to offer is spammy.

• Keep your subject lines short and compelling. Don’t give away your whole email in the subject line, or the reader has no reason to open it. Think of your subject lines like calls-to-action, and design them accordingly. They should be informative without giving too much away, and attention-grabbing without being too spammy. Ask a question that the reader will want answered. Sum up your offer in a few words. Convey a sense of urgency (“last chance,” “today only”). Highlight a benefit the recipient will get from opening the email. There are lots of ways to compose the subject line so readers click. Whatever method you choose, just be sure to keep it short. According to research by Retention Science, emails with subject lines of 6 to 10 words, or about 50 characters or less, have the highest open rates.

• Retention Science also found that including a recipient’s first or last name in a subject line improves open rates. By personalizing a B2B email subject line, your customers’ attention is captured. It sends a signal— “I should read the rest of this. It’s addressed to me.” If it fits your business model, personalizing an email by including your customer’s city or region is another effective way of generating interest and clicks.

Crafting the content inside a B2B email is important, but if your subject line is dry, uninformative or spammy, most customers won’t ever click on that content. Following these best practices will help your emails get opened and put your content in front of more eyeballs.