Maddy✉️ Composable all-in-one mail server.
HarakaA fast, highly extensible, and event driven SMTP server
smf-spfIt's a lightweight, fast and reliable Sendmail milter that implements the Sender Policy Framework
mailauthCommand line utility and a Node.js library for email authentication
toolbox-wikiInternet.nl toolbox - how-to's for modern mail security standards (DMARC, DKIM, SPF and DANE)
mailsec-checkAnother utility to analyze state of deployment of security-related email protocols.
Hermes-Secure-Email-GatewayHermes Secure Email Gateway is a Free Open Source Ubuntu 18.04 or 20.04 Server based Email Gateway that provides Spam, Virus and Malware protection, full in-transit and at-rest email encryption as well as email archiving. It features the latest email authentication techniques such as SPF, DKIM and DMARC.
thundersecThunderSec is a security plugin for Mozilla Thunderbird that creates several pieces of additional security functionality, including DNSBL, RBL, SURBL, DKIM and SPF.
spfParse SPF record and determine if client IP is allowed to send email.