How can you combine testing with Postmaster diagnostics?

Seeds and postmaster tools complement each other:

Seeds show what: Where messages actually land. Direct observation of placement.

Postmaster tools show why: Reputation scores, spam rates, authentication results. The underlying factors.

When seeds show poor placement, postmaster tools help diagnose the cause. When postmaster tools show declining reputation, seeds verify the impact.

Combined workflow: Test placement with seeds, then check Gmail Postmaster and Microsoft SNDS to understand the reputation context behind results.

Observe where your ships dock, then consult port authority records to understand why.