How to test deliverability without hurting reputation?

Testing deliverability requires methods that don't damage the reputation you're trying to measure.

Seed testing:

Maintain test accounts at major providers

Send test messages before campaigns

Check inbox versus spam placement manually

Rotate seed addresses to avoid caching effects

Inbox placement tools:

GlockApps: Automated placement testing across providers

Mail-Tester: Content and configuration scoring

Everest: Enterprise placement monitoring

These tools maintain seed lists designed for testing

Provider tools:

Gmail Postmaster Tools: Historical reputation data

Microsoft SNDS: IP-level reputation information

Aggregate data that doesn't require test sends

Safe testing practices:

Use actual campaign content for realistic tests

Test from production sending infrastructure

Verify authentication passes in tests

Check across multiple providers

What to avoid:

Testing on your actual prospect list

High-volume test sends that skew patterns

Using the same test addresses repeatedly

Ignoring test results that show problems