Gmail Blocking Email? Find Out Why and How to Fix It

Why Is Gmail Blocking Unauthenticated Email?

Support forums in recent months have been full of help requests from people having their emails rejected with an unauthenticated tin nhắn error message:

550-5.7.26 This mail is unauthenticated, which poses a security risk to tướng the sender and Gmail users, and has been blocked. The sender must authenticate with at least one of SPF or DKIM. For this message, DKIM checks did not pass and SPF kiểm tra for [domain] did not pass with ip: [IP address]. The sender should visit https://support.google.com/mail/answer/81126#authentication for instructions on setting up authentication. – gsmtp

If you visit the URL included in the error message, you’ll see Google’s authentication requirements for sending to tướng Gmail accounts.

These guidelines state that Google performs random checks on messages sent to tướng personal tin nhắn accounts to tướng ensure the emails have been authenticated.

It goes on to tướng specify that the tên miền your tin nhắn is sent from should have either SPF or DKIM records for authentication.

The 5.7.26 error above is triggered when an tin nhắn fails both of these authentication methods. The tin nhắn will also either be rejected or sent to tướng the spam thư mục.

Essentially, Google has tightened up on its security checks for tin nhắn to tướng try to tướng reduce the number of spam emails, phishing emails, and other malicious messages that are sent to tướng Gmail users.

Google and Yahoo’s New Mail Sending Requirements

Google isn’t the only mail provider that is adding extra requirements for mail received to tướng its users’ inboxes.

Yahoo has also announced that emails sent to tướng a Yahoo mailbox must be properly authenticated.

For Gmail, the new sender requirements will be enforced from February 1st, 2024, and Yahoo has also specified the first quarter of 2024. So if you haven’t already authorized your sending tên miền with SPF, DKIM, and DMARC, now is the time to tướng vì thế sánh.

For now, only bulk senders (those sending more than vãn 5,000 emails a day) will be affected by the new rules. But as these sender requirements have long been considered “best practice” for sending marketing and bulk emails, it’s recommended to tướng follow the guidelines even if you are sending fewer emails.

The new guidelines for both providers can be summarized as a few main requirements:

1. Authenticate outgoing email: Use industry standards such as SPF, DKIM, and DMARC to tướng authenticate your sending tên miền.
2. Enable easy unsubscription: Make it easy for subscribers to tướng remove themselves from your list in just one click.
3. Don’t send unwanted mail: Mail sent from senders with a spam rate above a certain threshold is likely to tướng be blocked. Spam rates should be below 0.3% and senders should aim for a spam rate of 0.1% or less.
4. Use a TLS connection for transmitting email: In December 2023, Google added this requirement for all senders who send mail to tướng Gmail accounts. Previously SSL connections, which are less secure, were acceptable but this will no longer be the case. You should kiểm tra the settings of your outgoing mail client and any software or ứng dụng using a custom SMTP tin nhắn connection to tướng ensure you have specified TLS as the security protocol.

What Are SPF, DKIM, and DMARC?

SPF and DKIM are authentication protocols that are phối up in the DNS records for your tên miền and are available for mail servers to tướng authenticate incoming emails.

Sender Policy Framework (SPF) prevents spammers or unauthorized users from sending tin nhắn that claims to tướng be from your tên miền. It includes a list of all IPs that are authorized to tướng send emails from your tên miền. When a mail server checks the SPF record, it will be able to tướng authenticate that your tin nhắn was genuinely sent from your tên miền or an approved IP. If you have not phối up an SPF record, this authentication kiểm tra will fail. 

DomainKeys Identified Mail (DKIM) verifies that messages sent from your tên miền have not been changed or tampered with since they left your outgoing mail server and were received by Google’s incoming mail server.

Domain Message Authentication, Reporting, and Conformance (DMARC) specifies what to tướng vì thế with an tin nhắn if either SPF or DKIM authentication fails.

DMARC authentication helps senders monitor emails sent from their tên miền, sánh they can quickly become aware of any mail spoofing attempts.

How to tướng Set Up SPF, DKIM, and DMARC to tướng Authenticate Your Emails

Your SPF, DKIM, and DMARC records are stored in your DNS settings, which you should find in the control panel for your tên miền. 

If you’re not sure where to tướng access your DNS settings, tương tác your trang web host or tên miền provider for advice.

You will need to tướng create the SPF, DKIM, and DMARC records to tướng add to tướng your DNS settings. The process for this can be a little complicated, sánh if you’ve not done it before, you should ask your tin nhắn service provider to tướng supply these or give you further instructions on setting them up.

Alternatively, you can use SendLayer to tướng phối up authentication for you.

SendLayer is an SMTP tin nhắn delivery service that improves your tin nhắn deliverability by authenticating your tên miền.

Additionally, SendLayer protects the sender reputation of your tên miền by setting up a subdomain for outgoing emails. The platform also includes tools for logging your emails and tracking tin nhắn delivery status, opens, and unsubscribes, sánh you’ll know immediately if there are any issues.

Setting Up E-Mail Authentication in SendLayer

SendLayer offers several plans, depending on the volume of emails you send each month. You can sign up by visiting the pricing page, choosing a plan, and clicking the Get Started button.

SendLayer also offers a không tính tiền trial, sánh you can try it out before signing up for a paid plan. To sign up for the không tính tiền trial, click the links at the bottom of the pricing table.

Once you’ve created your trương mục, log into your SendLayer dashboard.

Adding and Authorizing Your Domain

You will need to tướng add the tên miền you’ll be sending tin nhắn from to tướng your SendLayer trương mục. Click the Add Domain button in the top right to tướng enable SendLayer to tướng create SPF and DKIM records for your tên miền.

Type in your tên miền and click the Add Domain button.

SendLayer will generate 5 new DNS records for you. These records include:

• A record to tướng define a subdomain used exclusively for sending tin nhắn (this protects the reputation of your root domain)
• A DMARC record, which tells mail servers what to tướng vì thế if messages fail authentication
• An SPF record for authentication
• A DKIM record for authentication
• A TXT record to tướng verify tên miền ownership

You should add these DNS records to tướng your tên miền DNS settings in your trang web hosting trương mục or tên miền management control panel. See our complete tên miền setup guide for more help with this.

Once you’ve added all 5 DNS records to tướng your tên miền, go back to tướng SendLayer, tick the box, I have added these DNS records and am ready to tướng proceed, and click the Verify DNS Records button.

Note: changes to tướng your tên miền DNS settings can take time to tướng propagate across the mạng internet. You may need to tướng wait up to tướng 48 hours until SendLayer can verify your DNS settings.

To make sure your tên miền has been authorized, navigate to tướng Settings in the sidebar thực đơn of your SendLayer dashboard and scroll down to tướng the DNS Records và Settings section.

If SendLayer has been successful in verifying your domain’s DNS records, you will see a green checkmark in the Status column.

To use SendLayer’s SMTP for sending emails,  you’ll need to tướng configure custom SMTP settings on your trang web or use SendLayer’s API to tướng integrate with the platform that’s sending out emails on your behalf.

SendLayer integrates with WordPress, WooCommerce, Magento, and over 1,000 other apps. Read the getting started documentation for more information on integrating with SendLayer.

How to tướng Check if Gmail Is Blocking Emails From Your Domain

If Gmail is blocking your emails, they will be bounced back with an error message.

You should kiểm tra your mail server logs for errors regularly. If many emails are failing or bouncing, you should resolve the issue quickly to tướng avoid damage to tướng your sender reputation.

SendLayer includes tin nhắn logs in your trương mục dashboard and can send notifications of failed messages sánh you can be aware of any problems as soon as they occur.

If your tên miền has been added to tướng the Gmail blacklist, you will see error messages with the code 421 or 550. If this is the case, you will need to tướng tương tác Google to tướng submit an unblock request.

However, it can take weeks before Google removes your IP from its blocklist, and you’ll need to tướng prove you’ve taken steps to tướng improve your sender reputation. So it’s best to tướng follow best practices from the start to tướng avoid inadvertantly being blocked.

Best Practices for Sending to tướng Gmail Accounts

If you’ve phối up SPF and DKIM records for your tên miền and ensured your emails are being authenticated, there may be another reason why Gmail is blocking your emails.

Ensure you’re following these guidelines when sending tin nhắn campaigns to tướng subscribers who use Gmail.

• Send tin nhắn to tướng engaged users only: make sure subscribers want to tướng receive mail from you and clean your lists regularly to tướng remove unengaged users.
• Make it easy to tướng unsubscribe: Include a clear unsubscribe links in marketing emails and consider setting up one-click unsubscribe to tướng avoid spam complaints.
• Make sure recipients opt-in to tướng receive emails from you: Don’t automatically subscribe users to tướng mailing lists, and consider a double opt-in to tướng confirm before adding them to tướng a list.
• Increase sending volume slowly: It looks suspicious if you suddenly start sending a high volume of emails, particularly if your tên miền is new. Instead, increase the number of emails you send out slowly and consider spreading the emails you send over a period of time instead of sending mass emails all at once.
• Don’t purchase tin nhắn lists from other companies: While buying tin nhắn lists isn’t illegal in most locations, it’s certainly frowned upon, increases the risk a user will report spam, and can damage your sender reputation.

Prevent Mail Sent to tướng Gmail Users From Being Blocked or Sent to tướng Spam

Aside from these bulk sender guidelines, there are a few other things you can try to tướng make sure your transactional emails and other tin nhắn messages aren’t rejected or over up in the spam box instead of the Gmail inbox.

• Monitor the reputation of your sending domain: Gmail will block emails from your tên miền if it has a poor sender reputation. You can use a tool lượt thích Google Postmaster Tools (also take a look at our guide to tướng setting up Postmaster Tools) or MXToolBox to tướng kiểm tra your domain’s reputation
• Monitor the reputation of shared IP addresses: If your trang web is hosted on a shared server, it’s possible that other users on the same IP may have engaged in undesirable tin nhắn practices. Keep an eye on the reputation of your IP to tướng make sure it hasn’t been added to tướng any blocklists.
• Send tin nhắn from a subdomain: Setting up a subdomain that is used only for sending emails will protect the reputation of your main tên miền name.
• Monitor your tin nhắn bounce rate: Gmail may block emails you send if your bounce rate is high. While it’s impossible to tướng eliminate all tin nhắn bounces, you can use an tin nhắn suppression list to tướng remove invalid tin nhắn addresses and help keep your bounce rate to tướng a minimum.
• Keep marketing emails and transactional emails separate: Be careful about including promotional nội dung in transactional emails. While it’s generally okay to tướng send a coupon or links to tướng a promotion in a transactional tin nhắn from time to tướng time, keep this to tướng a minimum.
• Avoid sending emails with attachments or lots of images: Google may flag emails if the nội dung is suspicious or looks spammy.
• Write your tin nhắn subject lines carefully: Certain words can trigger spam filters, sánh be sure you’re following best practices for writing tin nhắn subject lines.
• Don’t send emails from a brand new domain: Gmail and other mail servers will often automatically reject emails if the tên miền has been recently registered and is sending out messages in bulk. If you just registered a new tên miền, it’s best to tướng wait a few months and warm up the tên miền gradually before you start sending emails from your site.

FAQs

We get a lot of tư vấn requests from users having issues with Gmail blocking their emails. Here are some of the most common questions we receive: