How to Fix Gmail Blocking Emails Issue [6 Easy Ways]

You are probably facing the “Gmail Blocking Emails” issue. If so, you are not alone! Every day, so many businesses face this problem.

Google is known for its strict spam filters, and in 2024, it introduced even stricter guidelines for email senders. If your emails don’t meet these new requirements, Gmail may block or reject them before they reach the recipient’s inbox.

In this guide, we will explain why Gmail might be blocking your emails, how to check if you’re affected, and what steps you need to take to fix the “Gmail Blocking Emails” issue.

Whether you run a business website or manage a mailing list, following these best practices will help you improve email deliverability and prevent Gmail from marking your messages as spam.

Ready? Let’s get started!

Why Is Gmail Blocking Your Emails?

Gmail may block your emails for two main reasons: your emails fail authentication checks, or your domain has been flagged as spam.

As we told you, Google has ramped up its filtering system to protect users from spam and phishing attempts, which means senders who don’t follow its guidelines may see their emails rejected or sent to spam folders.

#1: Your Emails Are Not Authenticated Properly

Many email servers allow unauthenticated emails to go through, but Gmail has become stricter about blocking such messages. If your emails lack proper authentication through SPF, DKIM, or DMARC, Gmail may reject them to prevent phishing and spoofing attempts.

Websites, especially WordPress-based, often send automated emails for password resets, contact form notifications, and order confirmations. Without proper authentication, these emails may never reach inboxes. Some users may experience intermittent delivery issues where emails work fine for a while but then suddenly stop. This usually happens when Gmail tightens its security checks.

A common sign of authentication failure is receiving a 550-5.7.26 error, which indicates that SPF and DKIM checks did not pass. If Gmail blocks your emails due to authentication issues, you need to configure SPF, DKIM, and DMARC records to verify that your emails are legitimate.

Here is how it looks: a user reported this error in Google’s support community thread.

#2: Your Domain Might Be In Google’s Spam Blacklist

Google uses automated systems to detect and block spam. With billions of Gmail users worldwide, it aggressively filters out emails that appear suspicious or come from domains with poor reputations. If multiple recipients mark your emails as spam, Google may flag your domain and add it to a blacklist.

Once blacklisted, your emails may get rejected outright or sent to spam folders. Gmail may return errors like:

• 421-4.7.0: Your IP address has been temporarily rate-limited due to suspected spam.
• 550-5.7.1: Gmail has detected unusual levels of unsolicited mail from your IP and has blocked your messages.

You can check if your domain is blacklisted using tools like MXToolbox. If you find your domain on a blacklist, you’ll need to take corrective actions, such as improving your email-sending practices and appealing to Google for removal.

Taking these steps can help restore your domain’s reputation and improve email deliverability to Gmail users.

How to Check If Gmail Is Blocking Your Emails

If Gmail is blocking your emails, you’ll likely receive a bounce-back message with an error code. These errors indicate whether your emails are being rejected due to authentication failures, spam filters, or a blacklist issue.

#1: Check for Bounce-Back Messages

When an email fails to reach the recipient, Gmail typically returns an error message. Pay close attention to codes like:

• 421-4.7.0 – Indicates temporary rate-limiting due to suspected spam activity.
• 550-5.7.1 – Signals that Gmail has permanently blocked emails from your IP due to spam-related concerns.

These messages suggest that Gmail has flagged your domain or IP, and you’ll need to take corrective action.

#2: Review Email Logs

Monitoring email logs helps identify patterns in failed messages. If multiple emails bounce back with similar errors, Gmail may have already blocked your domain. Many email services provide logs that track delivery failures in real-time, making it easier to spot issues.

#3: Use a Blacklist Checking Tool

Gmail may add your domain or IP to a spam blacklist if it detects suspicious email activity. Use tools like MXToolbox to check whether your domain appears on any major blacklists. If listed, you’ll need to follow the necessary steps to restore your domain’s reputation before Gmail removes the block.

#4: Submit an Unblock Request to Google

If your domain is on Gmail’s blacklist, you can submit a request to Google for removal. However, this process may take weeks, and you must demonstrate that you’ve fixed the issues that caused the block. Implementing best practices, such as proper authentication and reducing spam complaints, will improve your chances of approval.

By regularly checking logs, monitoring bounce messages, and keeping your domain in good standing, you can reduce the risk of Gmail blocking your emails.

What Are Google’s Email Sending Requirements?

Google has introduced stricter email-sending requirements to improve security and reduce spam. These guidelines, effective from February 1, 2024, primarily target bulk senders who send more than 5,000 emails per day, but following them benefits all email senders.

Other providers, such as Yahoo, have also implemented similar rules, making it essential to adopt these best practices to prevent email deliverability issues. Here are Google’s key email-sending requirements:

• Authenticate Outgoing Emails

Google requires all senders to authenticate their emails using SPF, DKIM, and DMARC. These authentication protocols help verify that your emails come from a legitimate source, reducing the chances of being flagged as spam.

• Enable One-Click Unsubscribe

Senders must include an easy way for recipients to unsubscribe from emails with a single click. This helps maintain a clean mailing list and prevents recipients from marking messages as spam.

• Keep Spam Complaint Rates Low

Google monitors spam complaints and expects senders to maintain a spam rate below 0.3%, with an ideal target of 0.1% or less. If too many users report your emails as spam, Google may block future messages from your domain.

• Use a Secure TLS Connection

Google now mandates the use of TLS encryption for all email transmissions. Previously, SSL was acceptable, but it is now considered less secure. You should check your email client and SMTP settings to confirm they are configured to use TLS.

Following these guidelines helps improve email deliverability, prevents Gmail from blocking your messages, and enhances the sender’s reputation. Even if you don’t send bulk emails, adopting these best practices will keep your emails from being flagged as spam.

6 Easy Ways to Fix the Gmail Blocking Emails Issue

If Gmail is blocking your emails, you need to take the right steps to fix the issue and improve your email deliverability. Whether your emails are failing due to authentication issues, spam complaints, or Google’s updated policies, these solutions will help you resolve the problem.

Now, let’s go through six effective ways to fix the issue and prevent Gmail from rejecting your emails.

Solution #1: Set Up SMTP for Sending Emails

If your WordPress site still relies on the default PHP mail function, Gmail may block or mark your emails as spam. To fix this, you need to use an SMTP plugin that properly authenticates your emails.

The Post SMTP plugin helps route your outgoing emails through a legitimate email service provider, improving your deliverability. It authenticates your messages, preventing them from being flagged as suspicious by Gmail’s spam filters.

Post SMTP comes with a user-friendly Setup Wizard that simplifies the configuration process. It supports multiple email services, including Gmail SMTP Server, Brevo, Microsoft 365 SMTP, SendGrid, Amazon SES, etc., making it a reliable solution for fixing email delivery issues.

By default, you see the following SMTP service providers in the setup wizard.

You can activate additional SMTP servers by navigating Post SMTP → Extensions.

For those who need extra features like email open tracking and detailed reports, upgrading to the premium version can provide additional benefits. However, the free version is enough to resolve most email-blocking issues.

For detailed instructions, check out our blog on how to fix the WordPress Not Sending Emails issue.

Solution #2: Configure SPF, DKIM, and DMARC

As we told you earlier, Google now enforces strict email authentication rules, which makes it essential to configure SPF, DKIM, and DMARC in your domain’s DNS settings. These authentication protocols verify that emails sent from your domain are legitimate, preventing Gmail from marking them as spam or blocking them entirely.

What Do These Records Do?

• SPF (Sender Policy Framework): Specifies which mail servers can send emails on behalf of your domain.
• DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails to verify authenticity.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): Instructs email providers on how to handle emails that fail SPF or DKIM checks.

If Gmail rejects your emails with a 5.7.26 error, your DNS records might be missing or misconfigured. A common issue is having multiple SPF records, which makes them invalid. To fix this, merge them into a single SPF record.

You should also check for a PTR record (Reverse DNS). While your email provider or hosting service usually manages this, confirming its setup can prevent future issues.

After updating your DNS records, test your email authentication. To do so, you can use our spam score checker.

NEED HELP? If you don’t know how to set up DNS records or find it difficult, feel free to contact us. We offer a premium service to every Post SMTP user, in which one of our technical email specialists sets up DNS records for you and professionally handles all your email-related issues.

Click here to schedule a consultation with our email specialist, who will fix all your email issues.

Solution #3: Use a Double Opt-in Strategy to Generate Leads

Google advises marketers to implement a double opt-in process when collecting email subscribers. This method requires users to sign up for your list and confirm their subscription by clicking a verification link.

Why Double Opt-in Matters?

Using a single opt-in can lead to higher spam complaints, which can negatively affect your sender’s reputation. Gmail tracks spam rates through Postmaster Tools, and a high complaint rate increases the chances of your emails getting blocked or sent to spam.

Although a double opt-in strategy may result in fewer sign-ups, it improves email engagement and deliverability. Subscribers who confirm their interest are more likely to interact with your emails, reducing bounce rates and spam complaints.

By adopting this approach, you build a high-quality email list that helps maintain a strong sender reputation and prevents Gmail from blocking your emails.

Solution #4: Use Correct From Email Address

Your “From” email address plays a crucial role in email deliverability. This is the sender address that recipients and email providers see when they receive your messages. Using the wrong address can cause Gmail to flag or block your emails.

If you are a WordPress user, then you can easily change your “From” email address using Post SMTP settings under the Message tab.

You can also do it while you are configuring the Post SMTP using the setup wizard, which you can see below:

Best Practices for “From” Email Address

• Use an Email Address That Matches Your Domain: Sending emails from an address that belongs to your domain (e.g., contact@yourdomain.com) improves authenticity. Gmail is more likely to block emails if the domain authentication does not match the sender address.
  
• Avoid Using Generic or Fake Addresses: Avoid sending emails from noreply@yourdomain.com or other non-existent addresses. Instead, use a real email address that recipients can reply to. This increases credibility and reduces the chances of your emails being marked as spam.

🚨 If you don’t have a custom email domain, check out our guide on How to Get an Email Domain for Your Business – 100% Free

Using a consistent and authenticated sender address helps prevent Gmail from blocking your emails and improves overall deliverability.

Solution #5: Add “Unsubscribe” in Your Marketing Emails

If you send marketing emails, adding an easy-to-find unsubscribe link is essential. Google requires senders to include a clear way for recipients to opt out of emails, and failing to do so can lead to your messages being flagged as spam or blocked entirely.

Understanding Marketing vs. Transactional Emails

• Transactional Emails: These include essential messages like password resets, order confirmations, and account notifications. Since they are crucial for users, they don’t require an unsubscribe option.
• Marketing Emails: These are promotional messages about your products or services. Gmail enforces strict rules for these emails, including the requirement to provide an easy way to opt-out.

Best Practices for Unsubscribe Compliance

• Include an Unsubscribe Link in the Footer: Every marketing email should have an unsubscribe link. The link must be visible and not hidden in the email design.

• Enable One-Click Unsubscribe in Gmail: Gmail displays an instant unsubscribe button at the top of marketing emails. To activate this, your emails must include list-unsubscribe headers in the email settings.

• Avoid Mixing Transactional and Marketing Content: Keep transactional and marketing emails separate. Don’t include promotional content in essential messages just to bypass unsubscribe rules.

Adding a simple and visible unsubscribe option improves email deliverability, reduces spam complaints, and keeps your marketing emails compliant with Google’s requirements.

Solution #6: Stay Informed with Google Postmaster Tools

Google Postmaster Tools provides valuable insights into how Gmail perceives your emails. If your messages are getting blocked or landing in spam, this tool can help identify potential issues and improve your email deliverability.

Why Use Google Postmaster Tools?

• Tracks your spam complaint rate to show how often recipients mark your emails as spam.
• Offers insights into domain reputation, IP reputation, and authentication status (SPF, DKIM, DMARC).
• Helps diagnose email deliverability problems, so you can take corrective action before Gmail starts blocking your messages.

Understanding Spam Complaint Rates

Gmail monitors how many users report your emails as spam. If your spam complaint rate exceeds 0.1%, you could face deliverability issues, and at 0.3% or higher, Gmail may block your emails entirely.

Spam complaints can arise if:

• You send emails to people who didn’t expect to receive them.
• Your emails lack an easy unsubscribe option, leading recipients to mark them as spam.
• Spam messages pass through your website forms, damaging your domain’s reputation.
• Your WordPress site is compromised, allowing unauthorized email activity.

Regularly monitoring Google Postmaster Tools helps maintain a healthy sender reputation, reducing the chances of Gmail blocking your emails.

Best Practices to Avoid Gmail Blocking Emails Issue

Following Gmail’s email-sending guidelines help improve deliverability and reduce the risk of your messages being blocked. Even if you have configured SPF and DKIM correctly, Gmail may still flag emails due to other factors. That’s why adopting these best practices can enhance your email performance.

• Send Emails to Engaged Users

Regularly clean your email list and remove inactive subscribers. Sending emails to disengaged users increases the likelihood of spam complaints, negatively impacting your domain’s reputation. Focus on sending emails to recipients who actively interact with your messages.

• Provide a Clear Unsubscribe Option

Every marketing email should include an easy-to-find unsubscribe link. Implementing a one-click unsubscribe feature can reduce spam complaints and improve trust with recipients.

• Use Double Opt-in for Subscriptions

Avoid adding users to mailing lists without their explicit permission. A double opt-in process helps confirm subscribers’ interest, reducing spam reports and increasing engagement rates.

• Gradually Increase Sending Volume

A sudden spike in email volume, especially from a new domain, can raise red flags with Gmail. Gradually increase the number of emails you send over time. Spreading emails across different time slots instead of sending them all at once can also help maintain a positive sender reputation.

• Avoid Purchasing Email Lists

Buying email lists may seem like a quick way to grow your audience, but it often leads to low engagement and high spam complaints. Gmail tracks sender reputation, and using purchased lists can harm your ability to deliver emails successfully.

By following these best practices, you can improve email deliverability, maintain a strong sender reputation, and build trust with Gmail users.

To Sum It Up

Gmail’s strict email filtering system can cause the “Gmail Blocking Emails” issue if you don’t follow its guidelines. However, by implementing the right strategies, you can prevent Gmail from blocking your emails and ensure they reach the recipient’s inbox.

Here’s a quick recap of what you need to do:

• Authenticate your emails using SPF, DKIM, and DMARC.
• Use an SMTP plugin like Post SMTP for reliable email delivery.
• Keep spam complaints low by using a double opt-in strategy.
• Ensure your “From” email address matches your domain.
• Add an easy-to-find unsubscribe link in marketing emails.
• Monitor your email performance with Google Postmaster Tools.

Need help? Contact the Post SMTP team of email specialists for expert assistance!