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According to Statista, nearly 50% of all email traffic is spam. Often times for businesses though, our emails end up in the spam folder even when they should not be categorized as such. In this post, we are going to cover a complete guide on how to stop your emails from going to spam.

First, let’s cover the most common reasons emails go to spam. Then, talk about how spam filters work, and finally discuss strategies to prevent emails from going to the spam box.

Common Reasons Emails Go To Spam

It is not always possible to find the exact reason an email went to someone’s spam folder, but avoiding these items can lead you in the right direction.

Here are the most common reasons emails end up in the spam folder:

  • Lack of proper authentication – This is typically where we suggest focusing your efforts first. Your domain should have proper DNS records to authenticate your email. Your email authentication method will vary depending on the platform, but here’s an awesome guide.
  • Misleading or inaccurate sender information – Your “From” line in your emails should tell the recipient who sent the message. If the ‘From’ field contains random characters, and numbers, and is unprofessional, or misleading, some spam filters might catch it.
  • Misleading subject lines – Keep your subject line focused on the message content and avoid spammy words/phrases, such as “BUY NOW!” or lots of “!!!” or emojis.
  • Poor email domain reputation – Every domain has an email reputation, like a credit score. If you send a lot of spam, expect more email service providers to block your content. Check your email domain reputation here.
  • Phrases/words that trigger spam filters – Avoid common phrases and words used by scammers such as “free”, “no-cost”, “easy money”, “buy now”, and so on. Basically, avoid excessive sales language and capital language.
  • Bad links – Avoid placing bad links in your emails. Many email service providers will block emails with lots of links or bad links that have the potential to include malware or phishing attacks.
  • Sending attachments – Attachments are a big red flag for spam filters, especially if you add too many. Emails with too many attachments are unlikely to make it to recipients’ inboxes.

You can check out some other mail marketing best practices here.

How Do Spam Filters Work?

There are many different types of spam filters and they function in different ways. Here’s a breakdown of the different spam filters.


Header filters evaluate the heading of the email. Usually, that is your email authentication methods, the from email, the subject line, and the email relay chain. The email relay chain is data left by email servers to see where the email originated from.


Content filters evaluate the content of the email. This involves looking for bad links, excessive links, too many attachments, and sales words/phrases. There are also many algorithms that evaluate senders’ content over time and become increasingly effective at scoring email content for spam.


Blacklist filters block senders based on IP. This can be done by email service providers or the individual user receiving the email. Blacklisting often refers back to a sender’s email domain reputation.

Strategies To Keep Your Emails From Going To Spam

Now that we have covered the top reasons emails go to spam and how spam filters work, let’s talk about strategies to keep your emails from going to spam.

Adhere To Email Marketing Laws

First, you need to adhere to email marketing laws. The Federal Trade Commission has a law called the CAN-SPAM Act. It’s an email marketing compliance guide for businesses that covers acceptable email marketing practices.

The CAN-SPAM act covers the following:

  • Don’t use false or misleading header information.
  • Don’t use deceptive subject lines.
  • Identify the message as an ad.
  • Tell recipients where you’re located.
  • Tell recipients how to opt out of receiving future emails from you.
  • Honor opt-out requests promptly.
  • Monitor what others are doing on your behalf.

Basically, follow the law and you’d stay out of most email spam filters.

You can read more about the CAN-SPAM Act here.

Use A Professional Email Address

Next, you need to use a professional email address. This means using a company domain to send your emails from like rather than a free email like,,, etc.

Using a professional email address lets email service providers (ESPs), track your domain and give you a rating. In addition, it lets recipients see who exactly the email is from.

Check Your Email Authentication Method

Next, you should check your email authentication method. This will depend on your email provider. The most common providers are Google and Microsoft which have support articles on how to authenticate your domain for sending emails.

You should ensure your domain name servers have SPF, DMARC, and DKIM records. Oftentimes, the support team with your email provider should be able to check your DNS to ensure email validation is set up properly.

Allow Individuals to Unsubscribe

If you are sending from an email list, you are required to have an unsubscribe button. We recommend having this unsubscribe button very clear so uses who want to can easily unsubscribe from your email list.

Without a clear unsubscribe option, users are more likely to report their email as spam and block their IP.

Cleanup Your Email Lists

Cleaning up your email list is a great habit to get into to only send emails to those that are engaging with your email. Many mass email software provides methods to remove unengaged contacts (contacts who do not open your emails), as well as, easily remove contacts who have bad emails.

Get into the habit of routinely cleaning up your email list so your emails are only going to contacts who are actually reading your email.

You can learn how to grow your email list here.

Force Users To Double Opt-In (Confirm Their Email Address)

Forcing users to confirm their email addresses when trying to opt into your email list can be a great way to ensure you are only getting active and engaged contacts onto your email lists.

You can learn the best email acquisition strategies here.

Email Your Contacts Regularly

You should email your contacts on a consistent basis so they become used to and expect your emails. Inconsistent emails and long periods before sending another email can leads to contacts forgetting about your emails and ultimately unsubscribing/marking them as spam.

Here is how to create an effective email newsletter.

Ask Subscribers To Whitelist Your Email

The easiest way to avoid spam folders is to ask each subscriber to whitelist your email. Each email program is going to have a different way of doing this. For example, with Google, you just need to add the “from” email to your contact list.

Grow Your Business With Email Marketing Today!

Email marketing is estimated to bring in a record 10.89 Billion dollars to businesses in 2023, according to Statista. If you are a business, you need to capitalize on the power of email marketing.

At WolfPack Advising, we help businesses manage their email marketing and set up marketing automation sequences to automate emails, SMS, and more! We specialize in email marketing for pest control companies and home inspectors.