Why people mark messages as spam and how to avoid it

Among the factors influencing deliverability, one of the most critical is the complaint rate.

This indicator is calculated by dividing the number of people who mark a message as spam by the total number of recipients. A high rate can seriously affect the sender's reputation and reduce the chances of future emails reaching the inbox.

If you are facing this problem, you are probably wondering:

"Why are we being marked as spam, if users subscribed to our list?"
"We are a legitimate sender with a valuable product, we don't spam!"

However, for recipients, spam is not just unwanted mail, but any mail that no longer interests them or that they consider intrusive. Let's see why this happens and how you can avoid it.

1. Lack of clear consent

A user may have provided his or her email address at some point, but that does not mean that he or she has given his or her email address. explicit permission to receive messages from your company.

There are different levels of consent:

• Implied permissionA user purchases a product or downloads a resource, but has not expressly indicated that he/she wishes to receive communications.
• Negative option: The subscription box is checked by default, which can lead to confusion and complaints.
• Explicit permission: The user has actively opted-in to receive emails, with no hidden tricks or conditions.

📌 Real case: A sporting goods company was sending emails about surfing to a user who, although he had interacted with them in the past, was no longer interested in that content. Failure to update the database resulted in the messages being considered annoying and marked as spam.

✅ Solution: It implements a double opt-in system to ensure that only really interested people subscribe. In addition, it allows you to manage content preferences.

2. Inadequate frequency and relevance

Sending too many irrelevant emails or messages can tire users, leading them to mark emails as spam instead of unsubscribing.

📌 Example: A user buys a gas barbecue and then receives emails with recipes instead of accessories related to his purchase. While this is not spam in the strict sense, the lack of personalization turns the message into a missed opportunity and increases the risk of complaints.

✅ Solution:

• Segment your list according to interests and behavior.
• Adjust the frequency of shipments according to the level of engagement of each user.
• Use dynamic content to personalize messages.

3. Poor management of lists and inactive contacts

Outdated databases increase the risk of spam. If you keep sending emails to users who no longer interact with you, the chances of complaints are much higher.

✅ Solution:

• Implement reactivation strategies for inactive contacts.
• If a user has not interacted in months, reduce the frequency of mailings or remove them from the list.
• Respects and processes unsubscription requests promptly.

4. Lack of authentication and unreliable design

Emails without authentication (SPF, DKIM, DMARC) or with misleading subject lines can generate suspicion and increase spam complaints.

✅ Solution:

• Make sure your emails comply with authentication standards.
• Use recognizable and reliable sender names.
• Avoid misleading or sensationalist subject lines.

Conclusion: Take care of your reputation and optimize your shipments

Reducing the complaint rate is key to improving the deliverability and effectiveness of your email marketing campaigns. Applying good practices in lead acquisition, segmentation and personalization will allow you to avoid your messages being marked as spam.

To ensure the success of your campaigns, we recommend you to use MasterBase®a leading email marketing platform with more than 20 years of experience in multiple countries. With its advanced segmentation, automation and analysis tools, you can optimize the delivery of your messages and improve your subscribers' experience.