How to keep your spam complaint rate low

Since social media platforms change their rules and algorithms all the time, your newsletter is your most important tool to connecting with your readers.

However, Google and Yahoo implemented new sender requirements in February 2024. Authors need to meet these requirements; otherwise, their newsletters will no longer reach their readers’ inboxes.

One of those requirements is authenticating your sender domain, and many of us probably gained a few gray hairs learning about SPF, DKIM, DMARC, and other things we never wanted to know.

But even if you’ve successfully got that done, there’s one more requirement to fulfill, and it’s an ongoing one you’ll have to keep in mind going forward:

Yahoo requires newsletter senders to keep their spam complaint rates below 0.3%, while Google advises to keep it below 0.1% and avoid exceeding 0.3%.

In this blog post, I’ll discuss some simple yet effective strategies to keep your spam complaint rate low, ensuring that your newsletters reach your readers’ inboxes consistently.

What is a spam complaint rate?

The spam complaint rate measures how often the recipients of your newsletter mark your emails as spam, either by clicking the “mark as spam” button in their inbox or by unsubscribing and choosing “these emails are spam” as the reason.

A spam complaint rate of 0.1% means 1 out of 1,000 people who received your newsletter marked it as spam.

What happens if you exceed a 0.1% spam complaint rate?

A high spam complaint rate signals to email providers like Google and Yahoo that your emails are spam that readers don’t want to see. Your sender reputation will suffer, which means more of your emails will either be rejected or end up in the spam folder. So now even readers who want to receive your emails are no longer seeing them.

How can you monitor your spam complaint rate?

To make sure you keep your spam complaint rate below 0.1%, of course you’ll need to track it.

The most precise way is to set up a Gmail Postmaster Tools account to track the spam complaints by Gmail users. It’ll show you not just your spam complaint rate but also your domain’s sender reputation. All you have to do to set it up is add another TXT record to your domain’s DNS settings.

If that sounds too complicated, you can of course also just check the reports in your newsletter service dashboard.

How can you avoid spam complaints?

Here are 10 tips on how to keep your spam complaint rate low:

• Only add subscribers to your mailing list who have explicitly opted in to receiving your newsletter. Adding subscribers without their express permission won’t just get you spam complaints, it’s also against the law (GDPR, CAN-SPAM, etc.). Never, ever buy a mailing list or swap lists with other authors! Be wary of promotions that tell readers to “sign up to win” a bunch of books. Readers often have to read the fineprint in the giveaway terms & conditions to find out that they will also be subscribed to dozens of author newsletters. Also don’t trick readers into subscribing. Your signup form should make it clear that they are signing up for your weekly/monthly newsletter. A newsletter signup form like the example below is not GDPR-compliant. The only thing this author is allowed to send subscribers is the free book they promised. Readers did not sign up for the newsletter and will rightfully click the spam button.

• Use double opt-in: Double opt-in means that a new subscriber will have to click a link in a confirmation email before they are subscribed to your newsletter. Yes, I know some experts advise you not to use double opt-in because you can build your mailing list faster without it. However, I firmly believe that quality is more important than quantity when it comes to newsletters. Double opt-in means only readers who really want your newsletter will receive it. It will not only lower your spam complaint rate but also your bounce rate—because if someone enters a fake email or an email address with a typo (e.g., bookreader@gnail.com), they won’t get subscribed.
• Set up an automated welcome email. If readers sign up for your newsletter but you don’t email them until several weeks later, they might have forgotten who you are and that they ever signed up, so they are more likely to mark your email as spam. To avoid that, set up an automated welcome message (or, even better, a series of welcome emails to introduce yourself to new readers) that are automatically triggered as soon as a new subscriber signs up for your newsletter. At the top of the first welcome email, remind your subscribers how they were added to your list. That means you need slightly different automations for each of your signup sources, e.g., your website, a cross-promotion, social media, etc.
• Set clear expectations. In your signup form and in your welcome email, let subscribers know what to expect from your newsletter. Will you email them weekly or monthly? What kind of content can they expect? Then, of course, stick to the expectations you set.
• Make your unsubscribe link easy to find. I’ve seen authors trying to hide their unsubscribe link by using tiny font or a light gray color on a white background. That’s not a good idea. If readers can’t find the unsubscribe link, they’ll mark your email as spam. Besides, you don’t want to pay for subscribers who are no longer interested in your newsletter. In addition to the one-click unsubscribe that your newsletter service includes in the header, I suggest still having an unsubscribe link at the bottom of each newsletter because that’s where most readers will look for it.
• Don’t send too many emails. If you send out your newsletter too often, it gets really annoying, and your chances of being marked as spam go up.
• Don’t send newsletters too infrequently. On the other hand, if you email your subscribers too infrequently, they will forget who you are and mark your emails as spam. The right frequency depends on you and your audience, but generally, I’d suggest emailing your readers no more than once a week and no less than once a month.
• Clean your list regularly. Make sure you don’t email subscribers who are no longer interested. Send a reengagement email to subscribers who haven’t opened or clicked any of your emails in six months, giving them a chance to unsubscribe or choose to keep getting your emails. If they don’t open or click a link in that email, unsubscribe them.
• Avoid spammy subject lines and emails. Yes, your subject lines should get your subscribers’ attention, but if it’s just clickbait and doesn’t match the content of your email, readers are more likely to report it as spam. The same will happen if your email looks spammy. Avoid text in all caps, multiple colors, or multiple fonts as well as spammy phrases (“buy now!”). I’ve seen author newsletters that consisted just of a dozen different BookFunnel promotions. Take a look at your newsletter from a reader’s perspective. Are you connecting with your readers, or are you basically just shouting “buy my book” at them?
• Use segmentation: Instead of sending every subscriber the same content, personalize what you include. For example, if your book is on sale in the US only, don’t send a newsletter about the sale to folks who live elsewhere. If you have a new audiobook out, promote it only to readers who listen to audiobooks. That way, your newsletter will feel relevant to your subscribers.

I hope these 10 tips will help you make sure your newsletter won’t be reported as spam and will keep landing in your subscribers’ inboxes!