Email Health
One-click domain scorecard — Blacklist, Mail Server, Web Server, and Domain Name System (DNS) checks graded Errors / Warnings / Passed, MXToolbox-style.
Monitor this automatically
NetTests can run this check on a schedule, preserve historical results, compare changes over time, and alert you the moment something breaks.
Start monitoring free → See all monitoring productsFrequently Asked Questions
What does the Email Health scorecard check?
It runs four categories: Blacklist — whether your mail server Internet Protocol (IP) address is on major Real-time Blackhole Lists (RBLs); Mail Server — Mail Exchange (MX) records, Pointer (PTR) records/reverse DNS (rDNS), Simple Mail Transfer Protocol (SMTP) banner, and STARTTLS; Web Server — HyperText Transfer Protocol (HTTP) reachability of the domain; Domain Name System (DNS) — Sender Policy Framework (SPF), Domain-based Message Authentication, Reporting & Conformance (DMARC), and DomainKeys Identified Mail (DKIM) records. Each check is graded Passed / Warning / Error.
Why is my IP on a blacklist and how do I get removed?
Internet Protocol (IP) addresses end up on blacklists after sending spam, being part of a botnet, or failing authentication. Fix the root cause first, then submit a removal request on the blacklist's website. Spamhaus Block List (SBL)/Exploits Block List (XBL) and SORBS have self-service delisting. Spamhaus Policy Block List (PBL) listings are normal for residential IPs by design — use your Internet Service Provider (ISP)'s mail relay instead of direct sending.
What is PTR / rDNS and why does it matter for email?
A Pointer (PTR) record maps an Internet Protocol (IP) address back to a hostname (reverse DNS). Most receiving servers check that the sending IP has a PTR record matching its EHLO greeting. Missing or mismatched PTR records are a leading cause of email being rejected as spam. Contact your hosting provider to set the PTR record for your mail server IP.
My DMARC check is failing — where do I start?
Start with a monitoring-only policy: v=DMARC1; p=none; rua=mailto:dmarc@example.com. This sends aggregate reports without blocking mail, so you can see what's failing Sender Policy Framework (SPF)/DomainKeys Identified Mail (DKIM) alignment. Once you've fixed misaligned senders, move to p=quarantine then p=reject. Use Email Records Check to validate syntax.
How often should I run an email health check?
Run it whenever you change your email configuration or notice deliverability issues. Blacklist status can change without warning — many teams run checks daily. Our Dashboard supports scheduled monitoring with alerts.