How to Fix “550 5.7 0 Email Rejected Per SPF Policy”

The SMTP error 550 5.7.0 Email Rejected Per SPF Policy means the receiving mail server rejected your message because the sending IP failed the sender domain’s SPF authentication check. It is an enforcement bounce — the sender’s SPF record explicitly told the receiver to reject unauthorized senders, and the receiver honored that instruction.

The three most common root causes are:

1. The sending IP is not authorized in the SPF record. If you recently added a new email service (a CRM, a newsletter tool, a support desk), its sending IPs or include mechanism must be added to the SPF record at the domain apex. Fix: add ip4:<address>, include:<vendor>, or mx as appropriate.
2. The SPF record has a syntax error or PermError. Per RFC 7208, any parse error or validation failure produces a PermError that causes the entire evaluation to fail-closed. Fix: run the record through an SPF checker to identify and correct the specific error.
3. The domain has multiple SPF records or exceeds the 10-DNS-lookup limit. RFC 7208 §3.2 requires exactly one SPF record per domain, and §4.6.4 caps total lookups at 10. Either condition triggers PermError. Fix: merge multiple records into one and flatten or remove excess includes.

This guide walks through diagnosing which of the three causes is hitting you using the full bounce message and an SPF record check, the specific fix for each, and how to verify delivery is restored after the fix propagates through DNS.

What is 550 5.7.0 Email Rejected Per SPF Policy” Error?

If you notice “550 5.7 0 email rejected per SPF policy,” your email server is probably incorrectly configured. This could be a result of various factors such as an incomplete or invalid SPF record, the presence of anti-spam tools like Sophos that prevent phishing and malware injection attacks, and sending emails through multiple servers, among others. 

If you think these discrepancies are impossible to fix and your email deliverability is out for a toss, hold tight!

How to Fix 550 5.7.0 Email Rejected Per SPF Policy” Error?

Rectify your SPF Record 

If your SPF record is invalid, you’re likely to receive this error message. In such cases, look out for the following red flags, in the SPF record and fix them to properly validate your domain name.

Some of the common errors in SPF records include:

• Spelling errors

• Uppercase letters

• Extra commas and spaces

• Additional dashes

Double Check Your MX (Mail Exchange) Record 

Another reason for the “550 5.7 0 email rejected per SPF policy” error could be invalid MX records. If the SMTP server detects discrepancies in the MX records— the sender domain is different than that mentioned in the record, it rejects the email. To fix this problem, make sure that your domain’s MX records are pointing to the correct server.

Include Third-Party Vendor IP Addresses in SPF Records

If your organization relies on third-party vendors that send emails on your behalf, make sure to incorporate their IP addresses in your SPF record. Most businesses overlook this crucial step, which results in a “550 5.7 0 email rejected per SPF policy” error. 

We understand that receiving a “550 5.7.0  email rejected per SPF policy” error can be frustrating, especially when it is your business’s bottom line and reputation at stake. It demands a methodological approach, technical know-how, and attention to every big and small detail. With the right kind of support and strategies, you can not only overcome this challenge but also safeguard your digital communications and maintain the trust of your clients and other stakeholders. Need help with it all? Trust our team of experts at AutoSPF to help you fix and optimize your SPF record. Contact us today to know more!