Error 550 rejecting for Sender Policy Framework protocol is triggered by misconfigured email servers for domains that cause email authentication issues. There are several reasons for misconfigurations. Let’s see what these errors are and list out solutions for them.
Error 550 Rejecting for SPF records- What Does This Actually Mean?
The problem occurs due to a misconfigured email server and can be resolved by making changes to your DNS records or by adding a TXT record to your DNS settings for SPF. Receiving this error means your recipient server failed the verification steps of the email sender’s identity.
Reasons Leading to Error 550 Rejecting for Sender Policy Framework
An invalid SPF Record
The deployment of a valid SPF record on your domain’s DNS is vital for the induction of the SPF verification process. Confirm this by looking up your domain’s SPF record online, followed by generating an SPF DNS record in case your organization’s domain lacks one.
Microsoft’s Spam Filters
Sophos, Microsoft’s anti-spam tool, offers a straightforward solution for safeguarding organizations and domains against online hackers and malware threats. Operating as a free service in the background of your computer, Sophos actively scans for compromised code, information, and spam emails, intercepting them before they reach your inbox or mail server. Additionally, it serves as a way to block the downloading of malicious software onto recipients’ systems.
It’s important to note that using Sophos on your system while relaying messages through Microsoft Office 365 Exchange online may lead to SPF failure. In such cases, emails may encounter the error message: “SMTP; 550 5.7.1 550 Message rejected because SPF check failed.”
Incomplete SPF Record
An SPF record begins with v=spf1 and ends with the ‘all’ mechanism, followed by a relevant qualifier. It includes IP addresses and other instructions for recipients’ servers to know how to deal with legitimate and illegitimate messages coming from your domain. Error 550 rejecting for Sender Policy Framework is mostly triggered due to missing out on mentioning aspecific sending sources.
Messages Relayed Through Multiple Intermediaries
On email forwarding, a message relays through multiple servers before reaching the ultimate destination, then the intermediaries are not likely to be listed in the SPF record, which is why your record ends up having an error 550 rejecting for Sender Policy Framework. This triggers email deliverability issues and impacts the company’s reputation.
This happens due to the fact that email header details get modified in transit, where the return-path address directs to the intermediary’s domain.
Spoofed Mail ‘From’ Address
Fake email ‘From’ addresses are employed to create the appearance of an email originating from a trustworthy source when, in fact, it is sent by a different party. Various techniques, such as manipulating headers and messages or exploiting a legitimate domain for malicious intent, can be utilized for this purpose.
The issue with this practice lies in the fact that messages employing spoofed mail ‘From’ addresses fail SPF checks due to the lack of alignment between the return-path domain and the mail ‘From’ domain (domain misalignment). The identification of a spoofing attack can result in a similar error response, leading to an error 550 rejecting for Sender Policy Framework.
Image sourced from digitalinformationworld.com
Final Words
Managing and monitoring SPF comes with challenges. To avoid an erroneous SPF record, it’s best to indulge in safe practices and give the responsibilities to IT experts specialized in email authentication.