Understanding Sender Reputation

Technical guide to how ESPs grade your emails.

The Silent Penalty of Cold Intro Forwards

Every time you forward a cold intro request to a contact who subsequently ignores it or marks it as spam, your domain's Sender Reputation takes a minor hit. Over hundreds of such interactions, this metric degrades silently.

The Big Three Metrics (2024 Standards)

  1. Spam Complaint Rate: Must stay below 0.3% (Google/Yahoo requirement). Even one mark on a small volume day can trigger filters.
  2. Engagement (Open/Reply): High engagement on double opt-in requests boosts your sender score.
  3. Authentication: SPF, DKIM, and strict DMARC alignment are non-negotiable baselines.
Crucial Insight: A forced mutual intro ("Alice, meet Bob") has a 14% response rate. A double opt-in mutual intro has an 86% response rate. ESPs track this delta.

Common Mistakes

FAQ

Can I repair a burnt domain? It is often faster and cheaper to migrate to a new domain than to rehabilitate a domain that has fallen into the 1-2% spam rate penalty box.