Shell scripts for taming the SPF (Sender Policy Framework) records in order to fight 10-maximum-DNS-look-ups limit.

Postfix SMTP relay docker image

Find Email Spoofing Vulnerablity of domains

Mail server

List of "big mailers" for OpenBSD's 'smtpctl spf walk' mechanism

Shell Script

Update ipset based on RIRs and GeoIP

📪 list mailservers from spf entries

It's an older email, sir, but it checks out - Email authentication checker

Bash script to detect SPF, DKIM, and DMARC issues that expose domains to spoofing

All-In-One Dockerized MTA (Relay Only) including Postfix, STARTTLS (Letsencrypt), SPF, OpenDKIM, OpenDMARC.

Docker Postfix SMTP Relay with support for rewriting canonical names

Bulk domain email security lockdown tool that prevents email phishing and spoofing attacks by automatically configuring SPF hard fail, null MX records, and DMARC rejection policies on unused Cloudflare-managed domains.

Check if a DNS zone is correctly set compared to its known value.