SPF

Sender Policy Framework

An email authentication method designed to detect forging sender addresses during email delivery. SPF allows the owner of a domain to specify which mail servers they use to send mail from that domain. It’s a way to prevent spammers from sending messages with forged From addresses at your domain. Here’s how SPF works:

1. Domain owners publish SPF records: These are TXT records in the DNS (Domain Name System) that list the mail servers authorized to send emails on behalf of their domains.
2. Email servers check SPF records: When an inbound mail server receives an email, it checks the SPF record of the sender’s domain to verify that the email is coming from a listed server.
3. Decision on Email Delivery: If the email comes from a server listed in the SPF record, it’s considered authentic. If not, it could be marked as spam or rejected.

Examples of SPF records:

• A simple SPF record might look like this: v=spf1 mx -all
  • v=spf1 indicates the version of SPF used.
  • mx means that emails are allowed from mail servers defined in the MX records of the domain.
  • -all indicates that emails from any other servers not listed in the SPF record should be rejected.
• A more complex SPF record: v=spf1 ip4:192.168.0.1/16 include:subdomain.domain.com -all
  • ip4:192.168.0.1/16 allows emails from a range of IP addresses.
  • include:subdomain.domain.com includes the SPF record of another domain, which is useful if you use third-party services to send emails.

Having a properly configured SPF record is vital. It ensures that emails sent from your domain are delivered to your customers’ inboxes and not marked as spam, maintaining the integrity and reliability of your email communication channels.

• Abbreviation: SPF