SPF Sender Policy Framework

Summary & Resources

sender policy framework (SPF) record is a type of DNS TXT record that lists all the servers authorized to send emails from a particular domain.

• DNS SPF record overview - Cloudflare
• Open spf - SPF Record Syntax
• Email Spoof Test

How it works

Mechanisms

"+" Pass
"-" Fail
"~" SoftFail
"?" Neutral

The "all" mechanism

Allow domain's MXes to send mail for the domain, prohibit all others

v=spf1 mx -all

The domain sends no mail at all

v=spf1 -all

The domain owner thinks that SPF is useless and/or doesn't care.

v=spf1 +all

Settings up a DNS record for SPF fail all that are not included

spf
Type: TXT
Name: @
Content: "v=spf1 include:_spf.mx.xyz.net -all"

Tools

• DMARCShield github DMARCShield is a Python program for email authentication and security. It offers a DMARC checker to ensure domain security, and a spoofing email sender to test for vulnerabilities. Protect your email communication and keep your domain safe with MailSecure.