Guide

Sender Reputation & Blocklist Checking: A Practical Guide

Sender reputation and blocklist status decide whether your email reaches the inbox before a single word of copy matters. Here's how both work and how to check them.

Updated August 2026

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What sender reputation is

Sender reputation is a mailbox provider's ongoing trust score for a sending domain or IP, built from bounce rates, spam complaints, engagement, and authentication history. It directly determines whether future email lands in the inbox — a good subject line cannot compensate for a poor reputation.

Why blocklists matter

Domain and IP blocklists are shared industry databases that mailbox providers consult when filtering incoming mail. Landing on even one major blocklist can suppress inbox placement across every provider that checks it, regardless of content quality — and it can happen without any obvious warning in your own sending logs.

How Aimly Audit approaches this

Aimly Audit checks your sending domain against blocklist databases and reports domain reputation alongside SPF/DKIM/DMARC status, so a reputation problem and an authentication problem don't get diagnosed as the same thing.

Domain blocklist status, checked directly
Authentication (SPF, DKIM, DMARC) validated alongside reputation, not separately
A single report instead of switching between multiple standalone checkers

Keeping reputation healthy day to day

Reputation is cumulative, not a one-time check — re-run a blocklist and authentication check periodically, and always after changing sending providers, DNS records, or sending volume.

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Check your domain's reputation

Aimly Audit checks blocklist status and authentication in one report.

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