“550 SPF check failed” – Here’s how to fix
Email errors are frustrating especially when you do not know the exact failure reason.
For example, bounce messages like “550 spf check failed” often confuse email users whether the error is at sender side or recipient side.
At Bobcares, we help website owners to solve complex email errors as part of our Outsourced Technical Support services for Web Hosts.
Today, we’ll see the top causes for “550 spf check failed” error and how we fix them.
What causes “550 spf check failed” error ?
Now, let’s check more on why this error happens.
SPF check is an anti-spam measure largely used in mail servers. Here, mail server checks the SPF (Sender Policy Framework) record of the domain to verify whether sender is genuine or not.
This SPF record contains the IP addresses of servers that can send mails on behalf of the domain. If the email originates from an IP listed in SPF record, recipient server accepts mail.
Likewise, when sending email from an IP address not available in SPF record, it results in a delivery status notification sent to the original sender:
"Error 550 - Message rejected because SPF check failed"
Similarly, in Microsoft Exchange mail server when using anti-spam solutions like Sophos, the error looks like:
SMTP; 550 5.7.1 550 Message rejected because SPF check failed.
Also, in social engineering attacks, to make the email look genuine, hackers can put anybody’s information in the “From:” line of web form. Note that this is the field that receiver will see.
In short, “550 spf check failed” means that the sender domain has wrong SPF record, or that the sender is using a spoofed mail ‘From‘ address.
How to fix “550 spf check failed” error?
Now, we know that SPF record check is causing the problems with mail delivery. Let’s see how we can solve this error effectively.
1. Correct sender SPF record
Although, this error is shown at the recipient side, the correction has to be done at sender domain.
That’s why, our Hosting Support Engineers first checks the spf record of the sender domain. Online tools like https://mxtoolbox.com/spf.aspx comes handy for this spf check.
Here, we need to confirm that the mail originates from the IP address mentioned in SPF record. And if there is a mistake, we inform the administrator of sender domain.com to correct these records. Otherwise, any other mail server checking SPF records will reject mail from that server.
2. Use valid sender
Additionally, there is a need to ensure that mail originates from valid sender. And, when mails sent from web forms shows error, our Dedicated Support Engineers double check the following things.
- “From:” field in the form uses the correct domain.
- Domain and its mail records (MX) is pointing to the correct server.
- Domain has correct SPF records.
After fixing these values, recipient server will identify the sender as valid and accepts mail.
“550 SPF check failed” error happens due to anti spam checks at recipient mail server. Today, we’ve seen the top causes for the error and how our Support Engineers fix the SPF failed error.