About SenderReputation.org
Free tools and educational resources helping email senders understand and improve their sender reputation.
Our Mission
SenderReputation.org exists to make email deliverability accessible to everyone. We believe that every sender — from solo entrepreneurs to large enterprises — deserves free, professional-grade tools to monitor and improve their email reputation.
Too many senders discover deliverability problems only after their emails stop reaching the inbox. Our goal is to provide the diagnostic tools and educational resources needed to catch issues early, fix them quickly, and maintain a healthy sender reputation over time.
Our Approach
The principles that guide everything we build.
Open and Transparent
Every tool shows you exactly what it checks and how results are determined. No black boxes, no hidden criteria. You see the same DNS data we see.
No Account Required
All tools are available instantly with no signup, no registration, and no email address needed. Just enter a domain and get results.
Privacy-Focused
We do not track individual users, sell data, or build profiles. Tool queries use only publicly available DNS data, and cached results are cleared regularly.
Free Forever
Our core tools and educational content will always be free. We believe access to deliverability intelligence should not be locked behind a paywall.
What We Offer
A comprehensive suite of free tools designed to analyze every aspect of your email sending infrastructure.
Our flagship tool that combines authentication, blacklist, DNS, and infrastructure analysis into a single Sender Reputation Score graded A through F.
Scans your domain and IP against the most widely used DNS-based blacklists to detect listings that could block your email.
Dedicated checkers for SPF, DKIM, and DMARC records that validate syntax, configuration, and best practices.
Step-by-step generators that help you create valid SPF and DMARC records without memorizing DNS syntax.
MX lookup, reverse DNS checker, and email header analyzer to troubleshoot mail server configuration and delivery paths.
Beyond tools, we maintain an extensive email glossary, in-depth deliverability guides, and a blog covering the latest in email authentication and reputation management.
How Our Sender Reputation Score Works
A proprietary methodology evaluating your domain's email health across four key categories, producing a weighted score from 0 to 100.
Authentication
SPF, DKIM, and DMARC record presence, validity, and configuration strength. Proper authentication proves you are who you say you are.
Blacklist Status
Whether your domain or associated IP addresses appear on any of the most widely used DNS-based blacklists. Even a single listing can severely impact deliverability.
DNS Health
MX record configuration, reverse DNS (PTR) records, and overall DNS infrastructure. Properly configured DNS signals a legitimate sending operation.
Infrastructure
Mail server responsiveness, TLS support, and general sending infrastructure quality. Modern mail servers expect secure, well-maintained peers.
Grade Scale
Ready to Check Your Reputation?
See how your domain stacks up with a free, comprehensive Sender Reputation Score.
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