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 lớn 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 lớn Gmail accounts.

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

It goes on lớn 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 lớn the spam thư mục.

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

Yahoo has also announced that emails sent lớn 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 lớn bởi so sánh.

For now, only bulk senders (those sending more than thở 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 lớn 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 lớn authenticate your sending tên miền.
2. Enable easy unsubscription: Make it easy for subscribers lớn 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 lớn 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 lớn 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 lớn 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 lớn authenticate incoming emails.

Sender Policy Framework (SPF) prevents spammers or unauthorized users from sending tin nhắn that claims lớn be from your tên miền. It includes a list of all IPs that are authorized lớn send emails from your tên miền. When a mail server checks the SPF record, it will be able lớn 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 lớn bởi with an tin nhắn if either SPF or DKIM authentication fails.

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

How lớn Set Up SPF, DKIM, and DMARC lớn 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 lớn access your DNS settings, tương tác your trang web host or tên miền provider for advice.

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

Alternatively, you can use SendLayer lớn 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, so sánh you’ll know immediately if there are any issues.

Setting Up Thư điện tử 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 phí trial, so sánh you can try it out before signing up for a paid plan. To sign up for the không tính phí trial, click the links at the bottom of the pricing table.

Once you’ve created your tài khoản, log into your SendLayer dashboard.

Adding and Authorizing Your Domain

You will need lớn add the tên miền you’ll be sending tin nhắn from lớn your SendLayer tài khoản. Click the Add Domain button in the top right lớn enable SendLayer lớn 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 lớn 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 lớn bởi if messages fail authentication
• An SPF record for authentication
• A DKIM record for authentication
• A TXT record lớn verify tên miền ownership

You should add these DNS records lớn your tên miền DNS settings in your trang web hosting tài khoản 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 lớn your tên miền, go back lớn SendLayer, tick the box, I have added these DNS records and am ready lớn proceed, and click the Verify DNS Records button.

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

To make sure your tên miền has been authorized, navigate lớn Settings in the sidebar thực đơn of your SendLayer dashboard and scroll down lớn 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 lớn configure custom SMTP settings on your trang web or use SendLayer’s API lớn 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 lớn 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 lớn avoid damage lớn your sender reputation.

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

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

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

Best Practices for Sending lớn 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 lớn subscribers who use Gmail.

• Send tin nhắn lớn engaged users only: make sure subscribers want lớn receive mail from you and clean your lists regularly lớn remove unengaged users.
• Make it easy lớn unsubscribe: Include a clear unsubscribe links in marketing emails and consider setting up one-click unsubscribe lớn avoid spam complaints.
• Make sure recipients opt-in lớn receive emails from you: Don’t automatically subscribe users lớn mailing lists, and consider a double opt-in lớn confirm before adding them lớn 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 lớn Gmail Users From Being Blocked or Sent lớn Spam

Aside from these bulk sender guidelines, there are a few other things you can try lớn make sure your transactional emails and other tin nhắn messages aren’t rejected or kết thúc 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 lớn setting up Postmaster Tools) or MXToolBox lớn 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 lớn make sure it hasn’t been added lớn 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 lớn eliminate all tin nhắn bounces, you can use an tin nhắn suppression list lớn remove invalid tin nhắn addresses and help keep your bounce rate lớn a minimum.
• Keep marketing emails and transactional emails separate: Be careful about including promotional nội dung in transactional emails. While it’s generally okay lớn send a coupon or links lớn a promotion in a transactional tin nhắn from time lớn time, keep this lớn 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, so 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 lớn 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: