[Guide Emailing] How not to be considered as spam?

We marketers have all heard colleagues say, “why do my emails end up in spam?” or “how to avoid being classified as spam?”.

These remarks raise a real problem concerning emailing today.

The deliverability of your emails can sometimes become very frustrating. Even the most skilled and rule-abiding email marketers will encounter email deliverability issues.

In this article, we are going to reveal some of our top tips to make sure your emails don’t go to spam and delivered to your recipient’s inbox.

Discover 8 emailing techniques to avoid falling into spam:

  1. Install a double opt-in system to avoid spam
  2. Monitor the performance of your email campaigns
  3. Build your own email database
  4. Regularly clean your email database and avoid being classified as spam
  5. Spam alert: give your users the choice of the frequency of your emails
  6. Authenticate your email with SPF, DKIM and DMARC
  7. Avoid blacklists and monitor your reputation
  8. Optimize your content so as not to alert spam filters

1- Install a double opt-in system to avoid spam

When building your email list, think about how you will check whether your recipients want to receive emails from you or your brand.

You can do this by using a double opt-in method that provides a subscriber with a welcome email that they must confirm before they officially end up on your mailing list.

The double opt-in method will provide you with proof that your recipient has a real interest in your emails (which will keep your engagement and your deliverability rate high).

Below is the example of Mailjet’s double opt-in when signing up for the newsletter.

Newsletter Mailjet opti-in LeDigitalizeur

2- Monitor the performance of your emailing campaigns

In order to stop being considered spamyou will have to analyze data.

Tracking the performance of your email campaigns, primarily engagement metrics, is the only way to know if you are performing better or better than before.

Before monitoring anything, it is important to choose basic metrics to analyze periodically in order to have a clear vision of your objectives and how to achieve them.

Here are some interesting metrics to watch:

  • The opening rate
  • Click-through rate
  • Spam complaint
  • Churn rate
  • Rebound rate

If you notice that your metrics are in the negative, don’t worry, but take action as soon as possible. For example, if your opening rates start to drop, analyze your object, do A/B testing and optimize it.

The frequency of your emails can also be a factor in lowering the open rate so be sure totry different sending frequencies.

3- Build your own email database

The tone and content of your emails are extremely important, but your content is meaningless if you broadcast it in front of the wrong audience Or to an unengaged audience.

This is why if you no longer wish to be considered as spam please always avoid:

  • Mass scraping of emails: this is definitely not the ideal solution if you want to land in your inbox.
  • Rent, buy a database
  • Share or use an email database with a partner

Building your database naturally is a long-term game that will benefit your business. It’s not the easiest acquisition lever to set up since it takes some time, but it’s the most efficient.

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4- Regularly clean your email database and avoid being classified as spam

From time to time, some of your contacts unsubscribe from your database. But keep in mind that many of those who no longer want to receive your emails will simply ignore your emails instead of unsubscribing.

This problem is harmful to your business because the lower your email engagement rate, the more ISPs will be watching you. This means your emails are more likely to go to the spam tab.

A smaller, more engaged email database always trumps a long list of unengaged contacts.

In order to prevent any blocking/restriction of your IP by access providers, and in order to combat the low engagement rate, consider regularly deleting users who do not engage and addresses that never receive your emails.

It is totally normal for you to experience unsubscribes, Don’t worry. On the contrary, it is a good sign and in the face of this risk, think about cleaning up your email lists in order to have better deliverability and no longer fall into spam.

5- Spam alert: give your users the choice of the frequency of your emails

A preference center allows subscribers to choose how often they want to receive your emails and reduces the risk of them unsubscribing and helps you avoid being considered spam.

Provide a center of preference simple and clear in order to offer the best experience to your users. You can of course combine the frequency of emails with highly targeted personalized emails thanks to marketing automation.

LeDigitalizeur preference center example
Credit: @Jess Hooper

Every recipient is different and a preference center helps your users find the frequency that works best for them and keeps engagement high. And higher engagement will help keep your inboxes and deliverability rates high and help prevent your emails from turning into spam.

6- Authenticate your email with SPF, DKIM and DMARC

Email authentication can be tricky and complex. But keep in mind that authenticating your email helps verify that you are who you claim to be. Also avoid using generic email addresses like: @gmail.com, @yahoo.com, @wanadoo.com, etc…).

Service providers, such as Google and Yahoo, trust authenticated email more and are much more likely to deliver messages from authenticated email to the inbox.

The following methods authenticate your emails and prove to ISPs that your email is worthy of the inbox and not the spam tab:

  • Sender Policy Framework (SPF): ensures that you are the sender you claim to be based on the sender’s IP address (found in the domain’s DNS record) with a list of IP addresses allowed to send from that domain.
  • Domain Keys Identified Mail (DKIM): guarantees that the email has not been altered during transmission.
  • Domain-based Message Authentication, Reporting and Compliance (DMARC): makes sure to deliver the email to the inbox when the first 2 steps are completed.

These adjustments must be made by you and not by your ESP. However, if you are at Mailchimp for example, you can find documentation on this subject.

7- Avoid blacklists and monitor your reputation

Your email domain has a reputation associated with it. This can very quickly deteriorate and you risk find on a blacklist. Unfortunately, even careful and well-meaning senders can end up on a blacklist.(ps: an IP reputation can be recovered after several months of non-use)

This is why we advise you to follow the steps to follow in order not to “rot” your IP:

  1. Use opt-in or double opt-in
  2. Implement an unengaged subscriber removal policy
  3. Use real-time address validation: If someone enters a fake email (or even a typo) and you send an email to that invalid address, your sender score suffers.

Many tools are also useful to know if your IP is blacklisted or not and to check if your email addresses are valid or not.

List of handy tools:

  • Email address validation: Hunter.io (solution made in France)
  • Blacklisted IP: mxtoolbox.com > blacklists
  • Check in which gmail tab the email appears: Litmus > gmail tabs
  • Rate the quality of your email: Mail-tester

8- Optimize your content so as not to alert spam filters

After having followed all the previous steps, it is now time to write your email. In order not to alert spam filters, we recommend that you follow a certain course.

  • Do not use or avoid to the maximum to use too attractive words like “free”, “guaranteed result”, etc…
  • Always send content on the same topic that subscribers have subscribed to.
  • Do not write capitalized words.
  • Respect a suitable image/text ratio (60% text, 40% images)
  • Think responsive. Knowing that most emails are opened on smartphones, don’t forget to make your email responsive for your audience to read.


Emailing is far from being an exact and easy science. Achieving sending the perfect email is impossible, but you can get close if you follow the emailing tips above.

Always keep in mind that the more your content will be attractive and consumed by your audience, the less likely you will be to fall into spam filters.

Emailing and its best practices are constantly evolving.

This is why we advise you to always inform yourself about the news and the latest emailing trends in order to optimize your deliverability as much as possible, to avoid being considered as spam and thus to increase your chances of reaching the boxes. receipt of your subscribers.