Domain owners may often come across the ‘550 SPF check failed’ error, which is generally triggered by the absence of a valid SPF record in the domain’s DNS. It also occurs if there is an invalid record present in the DNS of your domain.
It’s a configurational error that can be fixed at the sender’s end. All you have to do is either manually check mistakes in it or run it through an SPF record lookup tool, which will evaluate it for you and display errors existing in it.
How to Fix the Errors Detected During Manual or Tool-Based SPF Evaluation?
While you have the option to manually assess your record for errors, we highly recommend using an SPF record lookup tool. This method is not only more efficient, but it also reduces the risk of overlooking small mistakes. Regardless of the approach you choose, let’s explore the common errors and how to resolve them to eliminate the ‘550 SPF check failed’ error.
Spelling or Formatting Issues
An SPF record must follow a proper format; otherwise, it will be erroneous and thus invalid. Ensure it starts with v=spf1 and ends with -all, ~all, or ?all. Carefully look for extra spaces before or after the string, misspellings, extra dashes, uppercase characters, additional commas, and spaces.
The MX Record Must Point to the Correct Server
When someone sends an email, it’s routed from their device to a mail server, also called an SMTP server, that accepts or rejects the message based on factors like the IP address and other details in the email header.
When the server receives an email with invalid MX records, the ‘550 SPF check failed’ error prompts. To eliminate this error, carefully point your MX record to the correct server. Feel free to edit your MX record in your domains’ DNS.
Include the Sending Sources of Third-Party Vendors too
To ensure you include all your vendors’ IPs, you can either outsource your SPF management to a third party or maintain a manual list of sending sources. Update this list whenever you add an external tool or service for your emails.
Modify your domain’s records according to these updates, following the guidelines set by email service providers. For instance, if you use Exchange Online, refer to the Office 365 SPF record guide.
Ensure your SPF record includes both your internal IP addresses and those of your forwarders.
Microsoft Spam Filters
Apart from configuration, syntactical, formatting, and spelling mistakes you make, this error is also triggered by Microsoft’s anti-spam tool, Sophos. If you relay your emails through Microsoft Office 365 Exchange online, your messages may fail if Sophos is deployed at your end. In this situation, you will receive the ‘SMTP; 550 5.7.1 550 Message rejected because SPF check failed’ error message.
Sometimes, these issues can be difficult to spot and fix. Our team at AutoSPF can help you get rid of this error while also keeping your record within the DNS lookup limit of 10.
