We’ve all seen the “report as spam” button in our inboxes. As the recipient of an email, clicking that button reports a spam complaint – and for senders, the spam complaint rate is an important metric to monitor. This rate is expressed as a percentage and represents the ratio of complaints to emails sent.

Brands must focus on keeping this value low to avoid deliverability repercussions that can negatively impact your campaigns. In this article, we’ll walk you through you spam complaint rate so you can understand what to look for, why it matters, and how to keep it under control.

What is considered a high spam complaint rate?

The industry standard advises senders to maintain a 0.1% spam complaint rate or below. Meaning, if your campaign reports a 0.09% complaint ratio, you should be fine. However, a complaint ratio of 0.2% or above is considered high. Google and Yahoo recommend that every sender that sends more than 5,000 messages per day keep their complaint ratio below 0.3% to avoid negative consequences. To stay on the safe side, Acoustic recommends keeping your spam complaint rate at 0.2% or below.

What is the impact of a high complaint rate?

When the complaint ratio exceeds the recommended value, proprietary algorithms of the inbox providers such as Gmail or Outlook re-evaluate the IP/domain reputation. Those inbox providers consider a high complaint ratio as malicious, since a high ratio is often generated by phishing attempts or unsolicited campaigns. As a result, mailbox providers place the current or future campaigns originating from that sender in the junk folder. If the spam complaint ratio is continuously high, inbox providers might even prevent a sender from reaching the subscribers completely, throttling the IP address.

Why has my campaign been marked as spam?

The most common reasons for a subscriber to flag something as spam is being unfamiliar with the brand, being emailed too frequently, or receiving unexpected content.  

The most overlooked factor for brands is the frequency of sending. The email inbox is a personal channel and sending too many emails or too often can disrupt the subscriber's sense of peace, causing them to click the “report as spam” button. There is a lot of debate about the ideal sending frequency – but there is no one-size-fits-all answer, it depends entirely on your business type and your customers’ habits.

 

Tips for managing complaint rates

If you are having issues with your spam complaint rates, consider following these steps to help you minimize those complaints:  

1. Send the campaign to subscribers that gave explicit permission to be contacted and still remember your brand.  
2. Control the email flow so you don’t overwhelm your customers with too many campaigns.  
3. Make it easy for recipients to unsubscribe. Use one-click-unsubscribe if possible and make the unsubscribe link pop visually. Deliverability-wise, seeing some unsubscribes is healthy and getting a spam complaint is the exact opposite. 
4. Utilize segmentation to send personalized and relevant campaigns. 
5. Reflect your business in the domain configuration. Use a from domain that is easily recognizable. 
6. Refrain from sending to the dormant part of your subscriber list, or send a re-engagement campaign, removing inactive subscribers based on that. 
7. Protect your webforms from abuse by setting up double opt-in and captcha. 
8. Grow your list organically, without the involvement of third parties. 

 

For more email best practices, check out our on-demand webinar replay, Driving results through email: Maximize deliverability and engagement or download our ebook with Marketing Profs, How to make email work even harder for you.