There is nothing worse than spending hours perfecting your content, formatting it in aesthetically pleasing email, and sending it off to your carefully crafted contact list just to have your message go straight to spam, never reaching its intended recipient. Spam filters can prevent your readers from ever getting your messages, no matter how much work was poured into them!

Fortunately enough, there are some key ways to optimize delivery and keep your messages out of spam folders. We sat down with nine email marketing professionals to gather their best tips to increase delivery rates.

Spam Trigger Words

Once you have the deliverability side of things covered, such as domain authentication and blacklists, the content itself can sometimes be the trigger. Be careful what words you use, as spam filters are sensitive and can block you just for using certain words. We produced a swipe file with some of these words on our site.

Doug Dennison, MailNinja

“Sales-y” Subject Lines

Emails will go to spam if the subject line is too sales-y. Don’t promise the world in your subject line, especially with the words “free” or “act now.” These words tend to trigger the spam filter more often than other words and will do the opposite of what you intend to do. Make your subject lines reasonable yet actionable to attract your audience to open.

Vanessa Molica, The Lash Professional

Inability to Unsubscribe

One reason an email could be marked as spam is because they do not have the opportunity to unsubscribe, or the unsubscribe option is not visible at first glance. People want to know that they have the option to unsubscribe and the bottom line is, some people will, but when they cannot simply unsubscribe they mark it as spam. This will ultimately lead to a large number of spam complaints which then hurts your ability to reach a large number of people with future emails. Instead, make the option to unsubscribe clear for users who no longer want to receive emails.

Daniel Cheetham, Y Scouts

Spike in Abuse Reports

A sudden spike in abuse reports—for example, in the first moments right after a campaign lands in inboxes – can cause an entire server (Yahoo, Microsoft, etc.) to temporarily push all your emails to spam. To get around this, try staggering your send so you aren’t blasting 100k+ subscribers all at once. You might also change the subject line and resend at a later date to anyone who didn’t open the first time. I can often double the open rate of a campaign using this method.

Chryssa Rich, Primary Health Medical Group

Secondary Emails

People often use secondary addresses to sign up for lists, and may frequently change these as well. It’s a good practice to clean up your list from time to time by sending it through an email verifier program like Never Bounce, Clearout, or ZeroBounce (just to name a few).

Nicole Spracale, Coaching & Consulting

Image to Text Ratio

Emails often go to spam when they include multiple images or a large image-to-text ratio. To avoid this, make sure that you have a suitable amount of text included in your emails. Additionally, try to compress your image files before you include them.

Liam Quinn, Reach interactive

Low Engagement Rates

Emails go to spam when they have a low engagement rate. It’s so important to make sure your emails are being opened, read, and hopefully clicked on. You will be much more successful in email marketing to have a smaller list of active and engaging customers rather than mass emailing out to thousands of people hoping a small percentage open it.

Chelsea Lauridsen, Brand Marketing & Sales Executive

Spam Filters

Sometimes emails go to spam because filtering systems have become more diligent and many messages are getting flagged even though they are legit. When working with small business owners, I always provide them with one important tip. Once they add a new customer to their email subscriber list, make sure that the initial introduction email includes the request for them to add the business to their “approved contacts” list. By doing so, the filtering system will recognize your message as safe and keep it in the inbox rather than the junk folder.

Jennifer Leicht, Marketing and Small Business Consultant

Sounding Like a Robot

If your emails are slowly sounding and looking as if they are coming from a bot rather than an actual person, then they are likely going to be sent to spam. Remind your recipients that there is a human pressing the send button behind the email they signed up for. Make sure you are featuring their name in the email and that you are consistently updating the links and opportunities included in your emails. Include a fun P.S. at the bottom that is unique to your company or encourages your recipients to reach out!

Thylan Le, Markitors