An email authentication technique called Sender Policy Framework (SPF) uses DNS to control which IPs can send mail on your domain’s behalf. Administrators can establish soft fail and hard fail conditions for handling unauthorized mail using the syntax of SPF. We’ll use the more common, slang term hardfail even if the latter is formally referred to as just a fail in RFC 7208.
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What is SPF?
SPF is a crucial email authentication system that lowers the number of spammers who are successful online. Among other things, improper record setup might result in SPF failure.
The SPF record enables domain owners to specify which mail servers are permitted to send emails on their behalf. The SPF lookup tool checks the legitimacy of the sender domain in order to stop email spoofing and phishing.
The recipient’s email server may reject or flag the email as spam if it came from an unauthorized server. A crucial weapon in the fight against spam and phishing is the SPF service. Attackers will find showcasing themselves as reliable domains in their phishing emails more challenging.
How does SPF Work?
SPF is a TXT record that is made public in the DNS settings for your domain.
Every email you send ought to pass through the spam filters and firewalls of the receiving servers. This is like passing past a police checkpoint. The “police officer” will look up your driving history to determine whether you have insurance (or a current SPF record). If you do, they will check your insurance policy to see if you are listed as an authorized driver and then decide whether or not you are permitted to operate your vehicle.
Similar to the example above, the receiving mail server will run a DNS lookup on the message’s “From” address to determine whether the sender’s IP address or email service provider is authorized to send an email on that domain’s behalf. Authentication will succeed if the IP address is identified as a legitimate email sender in your SPF policy.
Your SPF record must include the sender’s IP address else SPF authentication will fail and your email will be less likely to be delivered. In order to stop email spoofing and unauthorized IPs from abusing that domain’s reputation, many internet service providers (ISPs) may block any IP addresses when SPF fails too frequently.
What is meant by SPF failure?
When everything is in order and SPF is successful, authenticating your email is simple enough. When SPF authentication fails, things become more complicated.
Any of the following causes can result in SPF failures:
SPF failure occurs when:
- Your domain contains several SPF entries.
- The DNS for the domain name could not resolve it for mail servers.
- The 10-DNS-lookup cap was exceeded by your record.
- It takes more than two void lookups to complete a single SPF check.
- Unable to locate the SPF record for the provided domain on a receiving email server
- The SPF record is not properly formatted.
- The IP address is not on the SPF record’s list of allowed addresses.
What is SPF soft Fail?
A status result known as an SPF soft fail indicates that the sender’s IP address is not authorized. The lack of a stronger limitation from the domain owner yields a stronger “fail.” By including an all mechanism in your SPF record, you can do this.
An SPF soft fail status indicates that the sender’s IP address is probably not authorized. Not having a stronger restriction imposed by the domain owner yields a stronger “fail.” You can do this by including an all mechanism in your SPF record.
As a result, a soft fail will occur for any IP address that is not specified in your SPF policy.
Depending on how you have configured DMARC in your email server, an SPF soft fail could be regarded as a pass or fail.
What is SPF hard fail?
When the IP address in emails comes from the recognized or authorized sender, it results in an SPF fail, also known as an SPF hard fail.
An SPF hard fail takes place when the IP address from which the email is getting originated is not listed as an authorized sender. SPF will fail if any unauthorized servers are detected, and the email messages may be completely deleted.
In order to avoid a hard fail, it’s crucial to publish your SPF record with the correct sending IP and email servers. An SPF failure is likely to fail in the DMARC SPF alignment.
What is the difference between SPF soft fail and SPF hard fail?
SPF Hardfail vs SPF Softfail
SPF Hard Fail
Emails may be fully blocked in cases of hard failures. Your emails may be completely ignored and fail SPF if you send emails from a server that isn’t listed in the SPF record.
SPF Soft fail
Soft errors may result in emails being categorized as spam or suspicious.
What are the other types of SPF failures?
- SPF None
Failure will also occur if there is no SPF record or if the record does not specifically establish a policy for the specified domain.
DMARC authentication similarly treats SPF none as a failure; since the SPF check failed, DMARC also fails. The final DMARC authentication check is also invalidated if your DKIM authentication fails.
- SPF Neutral
When the SPF record for your domain declares that it is unable to verify the authorization of the IP address, the record is said to be SPF-neutral. Using this method, any IP address will produce a neutral outcome.
In conclusion, understanding the difference between SPF hard fail and SPF soft fail can greatly improve the deliverability of your emails. While both options serve as a means of authenticating your emails, the way in which they handle failed authentication can have a significant impact on the success of your email campaigns.
If you’re serious about improving the reputation and reliability of your email communications, then it’s essential to choose the right SPF authentication method for your needs. Whether you opt for a strict hard fail or a more forgiving soft fail, taking the time to properly configure your SPF settings can help you achieve greater email deliverability and avoid the pitfalls of spam filters and other email security measures.
So why not take the first step towards improving your email authentication today? Whether you’re a small business owner or a seasoned email marketer, making the switch to the GoDMARC SPF policy can help maximize your email performance and reach more of your target audience than ever before.
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Q1: Does SPF hard fail or SPF soft fail prevent all email spoofing?
A: No, neither SPF hard fail nor SPF soft fail can prevent all email spoofing attempts. These methods provide a level of authentication, but other security measures such as DMARC should also be implemented to protect against email spoofing and phishing attacks.
Q2: Can I switch between SPF hard fail and SPF soft fail?
A: Yes, you can switch between SPF hard fail and SPF soft fail by modifying the DNS records of your domain. However, it’s important to understand the potential impact of these changes on your email deliverability and to test thoroughly before making any permanent changes.