Sender Score
Also known as: Validity Sender Score, Return Path Score
Validity's 0-100 reputation score for email-sending IPs, based on volume, complaints, spam-trap hits, and blocklist appearances.
Definition
Sender Score is a free reputation rating service operated by Validity (formerly Return Path) that scores email-sending IP addresses on a 0-100 scale. The score reflects an IP's sending behavior over the past 30 days: volume, complaint rate, spam-trap hits, blocklist appearances, and engagement metrics from major mailbox providers.
Scores above 70 indicate good reputation; mailbox providers are likely to deliver your mail to the inbox. Scores between 50 and 70 indicate marginal reputation; expect spam-folder placement at some providers. Scores below 50 indicate poor reputation; expect widespread delivery failures.
Sender Score is one of several public reputation indicators (alongside Cisco Talos, Google Postmaster Tools, Microsoft SNDS). It's particularly useful because it provides a single normalized number you can track over time, but it's not the only signal mailbox providers use — your actual deliverability depends on each provider's internal scoring.
Why It Matters
Sender Score is the easiest free benchmark for IP reputation. Looking up your score at senderscore.org takes 30 seconds and gives a directional view of your sending health. Monitoring it weekly catches reputation degradation before it shows up in inbox-placement data.
The biggest mistake is treating Sender Score as the definitive measure of deliverability. It's one input among many. A 95 Sender Score doesn't guarantee inbox placement at Gmail (Gmail uses its own algorithm); a 65 Sender Score doesn't necessarily mean delivery problems if your domain reputation is strong. Use it as one data point, not the whole picture.
Examples in Practice
A SaaS company checks Sender Score weekly. Their score has been 92 for months. Suddenly it drops to 71 — investigation reveals a spam-trap hit from a stale segment of their list. They suppress the segment, scrub the list, and the score recovers to 88 over the next 14 days.
A startup migrates to a new dedicated IP and notices the IP's Sender Score is 0 (no history yet). After 6 weeks of disciplined warming, the score climbs to 78. Inbox-placement testing confirms the warming was successful.
An agency monitors Sender Scores for all 12 sending IPs in their client pool. One IP drops to 45 due to a single client's poor list hygiene. They migrate the offending client to a separate IP and the pool recovers.