If your emails are getting lots of spam reports, you’ve probably developed the reputation of a spammer. Email service providers (ESPs) may start to filter your emails into spam folders, reducing your engagement metrics. What’s more, coming across as a spam sender can erode the trust your audience has in your brand. That can lead to lost customers, negative word-of-mouth, and, ultimately, a decline in your business growth.

But how do you know if you’re receiving too many reports? Large ESPs like Yahoo and Gmail have established a clear benchmark: your spam complaint rate shouldn’t exceed 0.3%, with the ideal metric being 0.1%.

For many companies, it’s easy to rack up reports:

• Some subscribers may find it more convenient to report your email as spam instead of unsubscribing.
• Others mark your emails as spam by mistake.
• 78% of consumers report an email as spam simply because “it looks like spam.”

If your spam complaint rate looks worrisome, it’s in your power to correct things and maintain good email deliverability. So, where do you start? Here are six common mistakes that could be causing your emails to be marked as spam.

Related: 5 Simple Tweaks for Better Email Deliverability

1. You never asked for permission

Sending emails without permission is one of the riskiest things you can do in your business. People don’t appreciate receiving emails they didn’t sign up for, and they’re likely to mark them as spam. This can quickly tarnish your reputation and hurt your deliverability.

To avoid this, get explicit permission before adding someone to your email list. Use the double opt-in method where subscribers confirm their email addresses so you can be sure they’d like to get emails from you. Respecting your subscribers’ preferences helps you build a long-lasting relationship with them.

2. People can’t unsubscribe

It’s a common reason consumers will mark an email as spam: they can’t find a way out. So, make it simple for recipients to unsubscribe if they no longer wish to get your emails.

“You shouldn’t have to jump through hoops to stop receiving unwanted messages from a particular email sender,” wrote Neil Kumaran, Google’s Group Product Manager, Gmail Security & Trust. Furthermore, he added that unsubscribing “should take one click.”

In February 2024, Google and Yahoo established new email-sending rules stating that:

• All emails must have a visible, functional unsubscribe link.
• User should be able to unsubscribe with just one click.
• Senders must remove unsubscribed email addresses from their lists within two days.

While common-sense in the email industry for decades, these guidelines are now hard rules if you send emails to Gmail and Yahoo users.

3. You use misleading subject lines

Your subject lines are the first impression your emails make in someone’s inbox, so it’s natural you want to make them catchy. But if they’re misleading or don’t match the email content, people will feel deceived and report your email as spam.

To avoid confusing your subscribers, think of subject lines as newspaper headlines. What’s the most newsworthy or compelling element in your email? Capture that in the subject and also remember to add preview text. Oftentimes, the preview text — which is the copy that goes right after your subject — can entice clicks more than the subject line itself.

4. You’re sending too many emails

Bombarding your subscribers with too many emails can overwhelm and irritate them, so they’re even more likely to hit the “mark as spam” button. Find a balance in your email frequency to keep your audience engaged without being intrusive.

An easy way to determine the number of emails you send is to go back to what you promised your subscribers when they signed up. If they opted in for your weekly newsletter, avoid sending them a deluge of additional promotional emails.

5. You send everyone the same email

Sending generic emails to your entire list without considering their preferences or behaviors can lead to disinterest and spam complaints. If subscribers don’t feel like your emails are speaking specifically to them, you’ll lose their attention within seconds.

Segmenting your list and creating more personal experiences for each group of customers and prospects is a much better approach. Once you set up these segments, you can easily continue adding new prospects to your funnels and sending them relevant emails.

Related: Inboxes Are Getting Overloaded. How to Keep Your Emails Out of Spam.

6. Your email design needs a revamp

It takes just seconds for someone to form a first impression about your email, and every element matters. Poorly designed emails with excessive images, no clear call-to-action, or too much text can appear unprofessional and trigger spam filters.

To avoid coming across as a spammer, pay attention to details like your sending email address, branding, layout and the image-to-text ratio. If you don’t love your email templates, chances are your subscribers won’t either. Consider revitalizing your design, ensuring everything is on brand, and making your emails easy to read.

Final tip: remove complainers immediately

I’m always astonished when a company emails me again after I report an email as spam. It’s a big no-no, as the only possible result is yet another spam report. So, set up a process that removes complainers from your mailing list right away. Stop reaching out to people who let you know your emails bother them and instead focus on those who open and click through your content. This is how you achieve better email deliverability and more successful email campaigns.