What is Sender Score and how does it relate to blocklisting?

Sender Score (operated by Validity, formerly Return Path) isn't a blocklist but a reputation scoring system that rates sending IPs from 0-100. While not a binary block/allow list, low Sender Scores contribute to filtering decisions at many mailbox providers and enterprise gateways.

Impact Level: Medium. Sender Score data feeds into Validity's commercial products and is referenced by many email professionals as a reputation benchmark.

How Sender Score works:

• Scores range from 0 (worst) to 100 (best)
• Based on complaint rates, spam trap hits, bounce rates, and other signals
• Updated daily based on rolling 30-day data
• Scores below 70 typically indicate deliverability problems

Score interpretation:

• 90-100: Excellent reputation, minimal filtering
• 80-89: Good reputation, occasional issues possible
• 70-79: Fair reputation, may see some filtering
• Below 70: Poor reputation, significant delivery problems likely

How to check: Visit senderscore.org (requires free registration)

Improving your score:

• Reduce complaint rates (target below 0.1%)
• Clean lists to eliminate bounces and traps
• Improve engagement through better targeting
• Maintain consistent sending patterns

Sender Score is your credit rating for email. It doesn't directly block you, but it tells everyone how trustworthy your sending history has been - and many act on that information.