What are spam complaints and how to minimize them

Spam has steadily grown since the early 1990s and is a real issue in the email community. As a result, the spam filter algorithm has evolved accordingly to improve the quality of incoming emails, by removing unsolicited spam and potential viruses. Avoiding spam filters is about staying compliant and understanding how your email campaign looks in its entirety.

This article covers the basics of spam filters, the new update that Google will enforce starting February 2024, and tips to keep spam complaints to a minimum for your email domain.

Overview of spam complaints

Spam filters use a lot of different criteria to judge incoming emails. Each factor is weighed and added up to assign a spam score, which determines if a campaign will pass through the filter. Passing scores vary depending on the server, so a campaign might pass through some filters but not others.

When engaging in email marketing, it's important to be informed of the major laws surrounding email and stay compliant. The CAN-SPAM Act of 2003 is "a law that sets the rules for commercial email, establishes requirements for commercial messages, gives recipients the right to have you stop emailing them, and spells out tough penalties for violations."  


Spam complaint rate 

To determine the spam complaint rate, you have to calculate the proportion of recipients who have flagged an email as spam concerning the total number of messages dispatched. For example, if you have sent 5,000 messages and 5 recipients designate them as spam, your spam rate would be 0.1% (5/5,000). 

Adhering to industry norms, an acceptable spam complaint rate is anything below 0.1%, equivalent to receiving one complaint for every 1,000 sent messages. Rates surpassing this threshold are deemed high, following the industry benchmark established by leading inbox providers such as Gmail.


How do recipients report spam complaints? 

Being mindful of these factors and regularly reviewing your unsubscribe and spam reports will contribute to a healthier email sender reputation.


User-initiated spam reports

  • Users may click the “this is spam” or “report spam” link/button in their inbox.
  • These actions are promptly communicated to us through established feedback loops with major inbox providers.
  • Typically, contacts reporting spam in this manner are automatically unsubscribed from your list.
  • It's important to note that the specific contacts using this method remain undisclosed.

Native unsubscribe link

  • Another way users express disinterest is by clicking the native unsubscribe link and indicating “Spam” as the reason.
  • You can track these instances through the unsubscribe report, which provides a campaign/automation email breakdown.
  • Keep in mind that emails unintentionally marked as spam contribute to your overall spam rate.

Understanding spam rate accuracy 

  • Not all Mailbox Providers share detailed information with senders, potentially resulting in an underestimation of your actual spam complaint rate.
  • Be aware that your true spam complaint rate might be higher than the visible statistics suggest.

What is the impact of a high complaint rate on the sender?

By following these guidelines, you can effectively manage and improve your email deliverability while mitigating the risk of account suspension.


Understanding the impact:

  • Elevated spam complaint rates can lead to persistent deliverability challenges, requiring months for resolution.
  • Keep in mind that major email service providers, like Gmail, closely monitor your spam complaint rate over a 30-60-day period.

Temporary email sending disablement

  • During the review period, sending emails from your account will be temporarily disabled to allow for a comprehensive assessment.
  • Once you respond and implement the recommended actions, normal email-sending capabilities will be reinstated.

Risks and account suspension

  • Maintaining a consistently high spam complaint rate poses the risk of account suspension.
  • It is crucial to adhere to the terms, which prohibit sending emails to recipients who haven't explicitly requested them.

The new Google email sender guidelines to avoid spam complaints, effective February 1, 2024


Follow these guidelines to ensure that your messages reach Gmail accounts seamlessly, minimizing the risk of Gmail limiting sending rates, blocking messages, or categorizing them as spam.

Requirements for all senders

  • Implement SPF or DKIM email authentication for your domain.
  • Verify that sending domains or IPs have valid forward and reverse DNS records (PTR records).
  • Utilize a TLS connection when transmitting email; refer to Google Workspace for TLS setup instructions.
  • Maintain spam rates reported in Postmaster Tools below 0.10%, avoiding a spam rate of 0.30% or higher.
  • Format messages under the Internet Message Format standard (RFC 5322).
  • Avoid impersonating Gmail From: headers, as Gmail is set to enforce a DMARC quarantine policy.

Requirements for sending 5,000 or more messages per day 

  • Set up SPF and DKIM email authentication for your domain.
  • Ensure valid forward and reverse DNS records (PTR records) for sending domains or IPs.
  • Use TLS connections for email transmission; follow Google Workspace for TLS setup details.
  • Keep spam rates reported in Postmaster Tools below 0.10%, avoiding a spam rate of 0.30% or higher.
  • Format messages according to the Internet Message Format standard (RFC 5322).
  • Avoid impersonating Gmail From: headers, considering Gmail's impending DMARC quarantine enforcement.
  • If regularly forwarding emails, add ARC headers to outgoing emails, signaling the message forwarding and identifying you as the forwarder.
  • For mailing list senders, incorporate a List-id: header specifying the mailing list in outgoing messages.
  • Establish DMARC email authentication for your sending domain, with the option to set the enforcement policy to none.
  • Ensure alignment of the domain in the sender's From: header with either the SPF domain or the DKIM domain for direct mail to comply with DMARC alignment.
  • Marketing and subscribed messages must facilitate a one-click unsubscribe, featuring a visible unsubscribe link in the message body.
  • If your daily email volume exceeds 5,000 before February 1, 2024, promptly adhere to these guidelines. Meeting these requirements before the deadline can enhance your email delivery. Failure to comply may result in unexpected email delivery issues or spam categorization.

How to identify you may have spam complaint issues

It's not always obvious if you have spam complaint problems. Here are a few ways to spot them:

  • Take a closer look at the stats in your campaign results 

See if you have a high rate of bounces consistently over multiple campaigns. Also, look at your open rates to see if they are in the single percentages.

  • Run a spam test

Services like Litmus help to check whether an email is ending up in Spam, using a series of standard filters, and testing with common email providers such as Gmail, Yahoo, Hotmail, etc.

  • Some other questions to trigger a spam flag

  1. Are you importing a purchased list of ANY kind?
  2. Are you sending to non-specific addresses such as sales@domain.com, business@domain.com, webmaster@domain.com, info@domain.com, or other general addresses?
  3. Are you sending to distribution lists or mailing lists that are sent indirectly to a variety of email addresses?
  4. Are you mailing to anyone who has yet to explicitly agree to join your mailing list?
  5. Have you falsified your originating address or transmission path information?
  6. Have you used a third-party email address or domain name without their permission?
  7. Does your email's subject line contain false or misleading information?
  8. Does your email fail to provide a working link to unsubscribe?"
  9. Are you failing to process any unsubscribe requests that come to you via a reply to your email within 10 days of the request?

If you have answered yes to any of the above questions, you may be labeled as a spammer.

Tips to keep spam complaints to a minimum

  • Get recipient permission 

Make sure your sign-up form comes with an explicit permission statement. This statement should indicate the type of content in your emails as well as your sending frequency (for example, weekly, bi-weekly, monthly). Limit sending marketing campaigns to those who have opted in.

  • Use double opt-in

The confirmation process means that anyone who signs up using your sign-up form will be sent a confirmation request email. They must click a link in that confirmation message to be officially added. This not only reminds your users that they signed up for your newsletter but also provides evidence that your list is entirely permission-based in the event you receive complaints. Furthermore, the double opt-in process helps maintain the quality of your list by preventing the accumulation of invalid or mistyped emails.

  • Add an unsubscribe link in a prominent place

Give the ability to your contacts to unsubscribe from your list if they wish. Opting for an unsubscribe button has no crucial effects on your deliverability, unlike a spam complaint. It is preferable to have recipients unsubscribe rather than marking your content as spam.

  • Send personalized emails, avoiding blasts and bulk campaigns 

Deploy automated messages that are personalized and tailored to the preferences of your customers. See if you can avoid mass campaigns to extensive lists.

  • Give subscribers the option to choose email frequency

Add a frequency preference setting to your subscription form so that subscribers can choose how often they would like to hear from you. Oftentimes, sending too much communication can burn out a subscriber and easily be reported as spam.

  • Identify the sender organization

Ensure that the From Address and all subject lines identify you and your organization. Many contacts will report an email as spam before opening it if they do not recognize the sender. If you have not emailed your customers within 6 months, we recommend using the confirmation process to invite them back to your list

  • Send emails with the same business domain

Mass email that comes from what resembles personal email addresses (those ending with gmail.com or yahoo.com) are often suspects of spam. We suggest you invest to register for a business domain to come across as a more professional organization.

  • Clean your subscriber list

By removing emails that lower your open rates and increase bounces, you can improve your overall email deliverability. Certain email services (e.g., Gmail) track the open rates of emails from your domain. Low open rates will likely be penalized by deliverability.

  • Avoid words that may trigger a spam alert

Using a lot of symbols or using all CAPS may trigger red flags for spam. Other examples include sales phrases such as "ACT NOW!", "100% FREE", "LIMITED TIME ONLY" which can also be suspected of spam. Try avoiding these trigger words in your subject line and messages as much as possible.

We monitor spam complaints across the platform

ContactPigeon constantly monitors the overall email deliverability across our platform. We enforce high standards across our customers, ensuring customers do not exhibit spamming practices and abide by our Terms of Use. This ensures all our customers best-in-class delivery rates.

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