Being in some warmup pools silently hurts your deliverability.

Trusting your warmup score by itself is a mistake — only a 3rd party can prove if you're at risk.

A sequencer can't independently verify its own pool quality. warm.ac is the 3rd party: public, free, live.

6+ million domains

Warmup ≠ warming

Deliverability problems you could not explain, until now. 3rd party analysis of 4 sequencers' warmup.

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This is huge.

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Industry composition ≠ Your composition

See exactly which inboxes your sequencer sends you to. The real picture, not the industry average.

Public Data

Public data

Sampled from our own mailboxes, cross-referenced against 6M+ tracked domains — every major sequencer in one place.

  • Pool composition: Google, Microsoft, SMTP
  • Bounce rate per pool
  • Pool quality trends, week over week
Explore the public index
Private Data

Your composition

Your real warmup, measured directly — not the industry average. It's live right now, the moment you connect.

  • Your exact sub-pool composition
  • Your real Google representation
  • Pool drift alerts the moment it moves

Takes 30 seconds. Your data loads instantly.

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will always be free.

Warmup ≠ warming

Deliverability problems you could not explain, until now. 3rd party analysis of 4 sequencers' warmup.

Go to section:

  1. 01

    The dip you couldn't explain

  2. 02

    How warmup actually works

  3. 03

    How cold email got here

  4. 04

    The consequence

  5. 05

    Why the industry misses it

  6. 06

    The proof

  7. 07

    The industry is responding

  8. 08

    This gets solved together

  9. 09

    What to do

  10. 10

    The bottom line

This is huge.

We'll be back soon.