What is SPF (Sender Policy Framework)?
Sender Policy Framework (SPF) is an email authentication method that helps to identify the mail servers that are allowed to send email for a given domain. By using SPF, ISPs can identify email from spoofers, scammers and phishers as they try to send malicious email from a domain that belongs to a company or brand.
How does a Sender Policy Framework (SPF) work?
Generally, a Sender Policy Framework:
1. Establishes a policy called an SPF record that outlines which mail servers are authorized to send email from that domain.
2. When an inbound server receives incoming mail, it references the rules for the bounce domain in the DNS and compares the IP address of the incoming mail to the authorized addresses defined in the SPF record.
3. The receiving server then uses SPF record rules to determine if the incoming message will be accepted, rejected, or flagged.
Importance of a Sender Policy Framework (SPF)
A Sender Policy Framework provides users with an additional layer of cybersecurity as it enables domain owners to create a list of approved inbound domains to minimize the risk of receiving malicious emails, and helps other servers verify your domain's legitimacy.
Without an SPF record, malicious actors may be able to spoof your domain and networks, harm your reputation and carry out cyberattacks that result in financial loss.
Furthermore, if you don’t have an SPF, servers that receive your emails may flag or reject them because they can't determine the authenticity of your domain.
The limits of Sender Policy Framework
Sender Policy Framework (SPF) is an email authentication protocol that can be used to prevent spammers and attackers from sending messages that appear to come from a trusted domain. Using the SPF email protocol, an organization can publish a list of authorized mail servers in an SPF record that appears in its DNS record. Receiving mail servers can perform an SPF test on every inbound email, checking to see if the IP address from which the email is sent matches an IP address in the domain's Sender Policy Framework record.
While the Sender Policy Framework offers a certain amount of protection against spam and spoofing, it is not a complete email security solution. A forwarded email will evade an SPF test, and the SPF protocol can't spot email that spoofs only the "from" address – the email address that's visible to users. Additionally, for Sender Policy Framework to work, organizations must keep their SPF records constantly updated – a time-consuming and cumbersome task that gets harder as companies change ISP providers.
DMARC, or Domain-based Message Authentication, Reporting & Conformance, offers an improvement on the Sender Policy Framework protocol as well as the DKIM protocol. DMARC prevents spoofing more successfully by requiring that the information in the "from" address align with other information about the sender, and it requires that a message is authenticated with either SPF, DKIM or both. DMARC also improves reporting and provides detail on how messages that fail authentication should be handled.
In the past, implementing DMARC authentication has been a challenge. The protocol can be difficult to deploy and hard to manage, requiring a significant investment of time and resources. To solve this challenge, Mimecast offers Mimecast DMARC Analyzer, an easy-to-use solution for streamlining DMARC implementation and management.
Mimecast DMARC Analyzer
As a 100% SaaS solution, Mimecast DMARC Analyzer helps reduce the time and complexity of enforcing a DMARC policy. DMARC Analyzer acts as an expert guide, helping organizations move toward DMARC authentication quickly and cost-efficiently.
DMARC Analyzer provides self-service tools that enable email administrators to:
- Gain the insight and visibility required before a DMARC reject policy is enforced to make sure email does not get blocked.
- Reduce the time, effort and cost of stopping domain spoofing attacks.
- Rely on user-friendly analyzing software to move toward a reject policy as fast as possible.
- Simplify deployment with a step-by-step approach.
- Achieve enforcement and monitor ongoing performance with easy to use alerts, reports and charts.
An easier way to authenticate email
Key features of DMARC Analyzer include:
- Quick and simple setup wizard for DMARC records.
- The ability to monitor DNS changes and receive alerts when DNS records are altered.
- User-friendly aggregate reports and charts for easier analysis and faster DMARC policy enforcement.
- Forensic reports that make it easy to identify and track down the sources of malicious email.
- Coverage for unlimited users, domains and domain groups.
- Summary reports issued daily and weekly to track progress over time.
- Two-factor authentication to enhance security.
- DMARC, DKIM and Sender Policy Framework record checkers.
- Managed services (optional) offered by Mimecast experts with proven deployment and project management expertise to minimize risk and deliver DMARC enforcement more quickly.
Additional email security solutions
In addition to DMARC Analyzer, Mimecast email security solutions include:
- Mimecast Secure Email Gateway. Using multiple detection engines and threat intelligence feeds, Mimecast blocks sophisticated and targeted threats at the gateway, including spear-phishing attacks, zero-day attacks, malware and spam.
- Mimecast Internal Email Protect. To stop threats that have landed internally or that are generated from within email systems, Mimecast scans all internally generated email for malicious links and attachments and suspicious content, detecting the lateral movement of attacks via email from one user to another.
- Mimecast Attachment Protect. Using multiple inspection analytics, Mimecast blocks threats embedded in attachments, using safe file conversion to ensure that users get immediate access to the attachments they need. This service also uses static file analysis, behavioral sandboxing and multiple antivirus engines to neutralize threats.
- Mimecast URL Protect. Mimecast delivers protection for malicious URLs on and off the enterprise network with every click, rewriting URLs in inbound emails and performing real-time scans on every link.
- Mimecast Impersonation Protect. Mimecast scans all inbound email for messages that may be attempting to impersonate a CEO, CFO or other executives as well as trusted partners and well-known brands.
Mimecast also offers a Web Security service that adds monitoring and security at the DNS layer to prevent malicious web activity and DNS spoofing and to block access to business-inappropriate websites.
FAQs: Sender Policy Framework (SPF)
What is a Sender Policy Framework (SPF) record?
An SPF record is a line of text that is stored in the DNS of a domain and specifies which IP addresses are approved for sending email for the domain. When a mail server receives an email, it can check to see if the IP address in the email's header matches the IP address in the SPF record. If the addresses do not match, the message will fail SPF authentication.
What is an SPF record check?
An SPF record check, or SPF validator, is a tool for determining whether an SPF record is valid. An SPF record checker looks up the record for a queried domain, displays any records found and tests the record to find any issues that could create problems for mail delivery.
Why do I need an SPF record?
You need an SPF record:
1. To verify that inbound messages to your server originated from domains you authorized.
2. To help servers you send emails to verify that your domain is authentic.