According to Statista, more than half of all emails are spam.

Needless to say, email spam is a huge problem on the Internet, which is why email services have become more aggressive in fighting spam.

Most emails filtered to spam are just spam. People would get annoyed if they had to manually filter through all these emails, so Internet Service Providers (ISPs) and email services (like Gmail) set up filters to automatically block spam before it shows up in the inbox.

However, if you make some common mistakes, your legitimate email can get swept up in these efforts to fight spam.

In this first part, we will discuss some of the most common reasons why emails become spam. Then, in the next section, we’ll share some tips to make sure you avoid the spam folder.

1. You haven’t set up proper authentication

One of the biggest problems with email spam is the lack of proper authentication.

Imagine when people call you on the phone:

• If you see it’s one of your contacts, you know exactly who to call.
• If you see a random number, assume it’s another robocall and ignore it.

It’s the same with email. There are technologies you can use to verify your email, which will automatically make you appear more trustworthy to spam filters. Instead of a random number, you’ve proven who you are and control the domain name you’re sending.

The biggest tricks are:

• DKIM (Domain Keys Identified Mail)
• SPF (Sender Policy Framework)
• DMARC – requires that you already use DKIM and SPF

If you use a custom email address and you haven’t set up these authentication methods, that’s one of the biggest reasons why your email is going to spam.

2. Your sender information is inaccurate or missing

In addition to the lack of technical authentication mechanisms such as DKIM and SPF, inaccurate sender information can also cause spam problems:

• To/from false information – Make sure the email address you send matches the sender and your verification information.
• Lack of Physical Address – The FTC requires that you add a physical address to your bulk emails. That’s why you’ll usually see an address at the bottom of every marketing email.

3. You use spam-inducing words or punctuation

Simply put, there are certain words or punctuation patterns that look inappropriate.

For example, “meet singles” or “online biz opportunity”. By themselves, these words may not be enough to get you into the spam filter. But they attract attention, and when combined with other problems on the list, your emails can end up going to spam.

Additionally, avoid other unsolicited tactics:

• All capitals
• So many exclamation points!!!!!!
• An onslaught of emojis ❤✨🔥👍🥺 (A few emojis are ok – don’t abuse them)

Similarly, using poor grammar or misspelled words can trigger spam filters, as many spammers use machine translation to translate their spam into English.

4. You are using a bad email list

If you’re sending bulk emails to a list of subscribers, there are a few things that can get you into hot water:

• Disallowed – If you don’t get a clear opt-in from subscribers, it can lead to spam problems.
• Stale List – If your list has too many inactive/disabled email accounts when emails bounce, they will appear spam to the filters.
• Low engagement – ​​If your emails have very low open rates, ISPs may take this as a sign that your subscribers don’t want your emails, which can increase their spam flag list.

5. You link to shady websites or use misleading links

The main purpose of most spam emails is to get you to click on some kind of link, so it’s no surprise that using the wrong kind of links can get you into trouble with spam.

Two main things can cause problems here:

First, you may be connected to a site that for some reason appears to be spam. For example, maybe it’s related to copyright infringement, infected with malware, or some other reason. Or, maybe it’s legitimate, but it’s too close to another spam domain.

Second, you may run into problems if the destination URL does not match the display URL. For example, if the display URL is https://google.com but the actual link is https://anotherwebsite.com, that can land you in trouble, as this is common tactic spammers use to trick people into clicking on links.

Similarly, using URL shorteners can cause problems for the same reason (you’re trying to trick people into clicking on links they might not otherwise).

6. You use too many pictures (or not enough text with pictures)

Images can cause you problems with spam filters.

There are two ways this can happen:

First, if your email doesn’t have a large image and text, it can trigger spam filters. This links to the “spam words” point above. To avoid collisions with spam filters for using spam words, some spammers moved to include all the text in a single image file rather than as actual text.

Because of this, sending a single image looks suspicious to spam filters.

However, you may face problems in the other direction. If you use too many images and too small a font, that can also get you into trouble.

Using images as a substitute for text can get you in trouble, don’t do it!

7. You are sending too many attachments

Because attachments are used to distribute malware or other malicious activity, they always attract attention from spam filters, especially certain file types (such as a .exe file).

8. Your recipient marked you as spam (perhaps by accident).

In most email clients, users have an option to manually mark emails as spam.

If the person you’re trying to email previously marked your email as spam, the new emails you send may also end up in the spam folder.

Additionally, if you send bulk emails, many people marking your emails as spam can negatively affect your reputation as a sender. This can increase the chances of your email ending up in spam, even when you’re sending it to people you haven’t marked as spam.

Six tips to improve email deliverability and avoid the spam folder

Now that you know what can go wrong, let’s get into some actionable tips you can implement to keep your emails out of the spam filter.

1. Use Mail Tester to diagnose problems

Mail Tester is a great free tool to diagnose technical issues with email deliverability. You should:

• Go to Mail Inspector
• Send an email to the address it provides (from the email account you have spam problems with). If you have problems with a specific email, be sure to use that text/image/link in your email.
• Click the Check Your Score button.
• See analysis.

Mail Checker will give you an overall score with some suggestions for improvement. You can expand each section for more information:

If your score is too low, you usually need to implement suggestions to improve your delivery.

2. Set up proper authentication

As the Internet has evolved, spam filters place more weight on the overall sender’s reputation than the content of your emails.

The content of your emails is still important, but someone with a solid reputation will be able to get away with some spam-adjacent content that a sender with a poor reputation can’t.

Making sure your emails are properly authenticated with methods like DKIM and SPF is one of the best ways to improve your reputation.

If you use a free service like Gmail, you don’t have to worry about this. This only applies if you use a custom email address like [email protected].

You can set up these authentication methods by adding TXT records to your domain’s DNS management.

You can get the reports you need from your email hosting service. Try searching the help documentation for “SPF” or “DKIM”, or ask the support team if you can’t find it.

Then, you need to add those records to your domain name using the DNS editor. You will do this:

• If you use your hosting name servers through your web hosting dashboard
• Through your domain registrar if you are not using your hosting servers

For example, here’s what it looks like to add a Zoho Mail SPF record through popular WordPress hosting company Kinsta’s DNS management tool:

3. Use a dedicated shipping service for your website

If you’re having spam issues with the emails that you send from your website, a great way to avoid problems is to use a dedicated email sending service (AKA SMTP provider) rather than trying to send from your host’s SMTP server.

This is especially true for WordPress sites. The default method that WordPress uses to send emails is almost certainly going to end up with your emails in spam folders a large percentage of the time.

Don’t worry! For a small site, you can find sending services that are 100% free. Usually, you’ll be fine on the free tier for up to ~300 emails per day.

4. Follow email design/copy best practices when sending emails

Once you’ve properly authenticated your emails, you’ll already be well on your way to avoiding the spam folder.

However, don’t forget the many designs and copy sins that we talked about:

• Don’t abuse images – don’t rely on a single large image or lots of small images. Use text/HTML instead of including everything in images.
• Avoid spammy copy – don’t use spammy words, avoid spelling/grammar issues, and don’t abuse punctuation/emojis.
• Avoid unnecessary attachments – don’t send attachments unless they’re necessary.
• Make sure to add sender information – for marketing emails, make sure to include your physical address and accurate sender information.
• Only link to reputable sites – don’t do anything that could be construed as “tricking” people into clicking links that they didn’t intend to visit.

5. Maintain your subscriber lists properly

If you’re sending emails to a list of subscribers, you’ll also need:

• Make sure your subscribers log in clearly.
• Periodically clean your list of dead/invalid accounts.
• Give subscribers a clear option to unsubscribe.

6. Ask recipients to whitelist your emails

Finally, if all else fails, you can always ask your recipients to whitelist your email address to prevent your emails from going to spam. You’ll see even big brands asking subscribers to whitelist their emails, so this isn’t a common strategy:

To make it easier for people, you can create a help document that shows you how to whitelist your email address in popular clients like Gmail.

Having your emails end up in people’s spam folders is frustrating. But after reading this post, you should know to understand why your emails are going to spam and fix the problem(s).

In most cases, the two biggest things that you can do are:

• Properly authenticate your emails.
• Use a dedicated sending service for your website’s emails (if you’re not already).

Beyond that, you’ll want to avoid spammy copy, use links and images appropriately, and make sure your subscribers are engaged and opt-in.