Sender Score
Sender Score is a numeric reputation rating (0-100) for an outgoing mail server IP address, calculated by Validity (formerly Return Path).
What Is Sender Score?
Sender Score aggregates data from ISPs and email networks to rate the trustworthiness of an IP address. A score above 80 is considered good, above 90 is excellent, and below 70 indicates significant deliverability issues. The score is based on 30-day rolling averages of metrics including spam complaint rates, unknown user rates (bounces), spam trap hits, and infrastructure factors. While Sender Score is specific to Validity's platform, similar reputation systems exist at every major ISP — Gmail has its own internal scoring, as do Microsoft and Yahoo.
Why It Matters for Newsletters
Your Sender Score directly correlates with inbox placement. Senders with a score above 90 typically see 90%+ inbox delivery, while those below 70 may see half or more of their emails filtered to spam. It's a useful benchmark for tracking your email health over time.
Best Practices
- Check your Sender Score regularly at senderscore.org
- Focus on the metrics that influence it: bounces, complaints, and spam traps
- Compare your score with industry benchmarks
- Use it as an early warning system — declining scores often precede deliverability problems
How Aldus Handles This
Aldus uses Resend's managed infrastructure, which maintains strong IP-level reputation. What matters most for your newsletters is domain-level reputation, which Aldus helps you build through proper authentication, list hygiene, and engagement optimisation.