Email domain reputation is the trust score that internet service providers (ISPs) and mailbox providers assign to your sending domain based on your historical sending behavior, authentication setup, and recipient engagement. A strong reputation means your emails reach the inbox. A damaged one means they go to spam \u2014 or get rejected entirely. This guide gives you the tools and practices to build and maintain a domain reputation that delivers.<\/p>\n\n\n\n
Your domain reputation is not a single number \u2014 it is a composite signal drawn from several metrics that ISPs use to judge whether your mail deserves inbox placement.<\/p>\n\n\n\n
Warmy.io.<\/strong> Warmy is an AI-driven email warmup and deliverability platform that automatically builds your sender reputation, improves inbox placement, and keeps your emails out of spam. Warmy’s free Email Deliverability Test shows you exactly where your emails land \u2014 inbox, promotions, spam, or unreceived \u2014 across Gmail, Outlook, and Yahoo, while also checking your blacklist status and verifying your SPF, DKIM, and DMARC setup.<\/p>\n\n\n\n SenderScore.<\/strong> SenderScore, operated by Validity, rates your sending IP on a 0-100 scale using a 30-day rolling average of complaint rates, spam trap hits, bounce rates, and sending volume patterns. A score above 90 indicates excellent deliverability; anything below 70 typically signals deliverability problems worth investigating.<\/p>\n\n\n\n GlockApps.<\/strong> GlockApps is an inbox placement testing platform that sends your email to a seed list of 70+ real addresses across Gmail, Outlook, Yahoo, and corporate mail servers, then reports exactly where each copy lands. It also includes DMARC analytics and blacklist monitoring.<\/p>\n\n\n\n Google Postmaster Tools.<\/strong> Google Postmaster Tools v2 is a compliance and monitoring dashboard for Gmail traffic. As of September 2025, the Domain Reputation and IP Reputation dashboards from v1 have been permanently retired. The new v2 interface focuses on compliance status, spam rate trends, and authentication pass rates. Keep your spam rate below 0.1% \u2014 Google’s bulk sender guidelines<\/a> recommend never exceeding 0.3%.<\/p>\n\n\n\n For a full breakdown of what causes deliverability failures and how to resolve them, the Warmy email deliverability audit guide<\/a> walks through every diagnostic step.<\/p>\n\n\n\n Sender Score.<\/strong> SenderScore measures your sending IP’s reputation on a 0-100 scale. Higher scores correlate with better inbox placement. A score above 90 gives you excellent deliverability with most providers.<\/p>\n\n\n\n Domain Reputation Score.<\/strong> Domain reputation is a separate signal from IP reputation. It evaluates authentication health, sending volume patterns, and complaint rates associated specifically with your domain. Mailbox providers now weight domain reputation more heavily than IP reputation \u2014 especially at Gmail \u2014 making this the metric that matters most in modern email environments.<\/p>\n\n\n\n Spam Complaint Rate.<\/strong> This is the percentage of recipients who mark your email as spam. Google’s bulk sender guidelines require keeping your spam complaint rate below 0.1%. Rates above 0.3% trigger active filtering and can permanently damage your reputation.<\/p>\n\n\n\n Bounce Rate.<\/strong> Hard bounces signal invalid addresses and poor list hygiene. A bounce rate above 2% is a red flag for ISPs. The M3AAWG Sender Best Practices guide<\/a> recommends suppressing hard bounces immediately after the first failure and running list validation before any high-volume send.<\/p>\n\n\n\n Not sure where your emails are landing right now? Run a free Email Deliverability Test<\/a> and find out instantly.<\/p>\n\n\n\nAnalyzing Reputation Metrics<\/h3>\n\n\n\n