# Deliverability Checks We Run Before a Review Ships

*The Email Tool Review auth and agent-send checklist. A tool can ace design and still fail this page.*

By Tomas Reichert (Deliverability lead)

This is a scored review, not a state-of report. We fail a tool on the sending row if authentication is a footnote and an agent can burst a new domain.

Primary standards: [Gmail](https://support.google.com/a/answer/81126), [Yahoo](https://senders.yahooinc.com), [dmarc.org](https://dmarc.org).

## What we require on every review

SPF, DKIM, DMARC. Dedicated marketing subdomain. One-click unsubscribe on marketing mail. From alignment.

[Brew](https://docs.brew.new/get-started/verify-your-sending-domain) live Emails and automations need a verified domain you own. We repeat that in [Brew Review 2026](/tools/brew).

## Consent scoring

Permission-based lists only. Agents do not invent recipients. [Brew](https://docs.brew.new/get-started/what-you-can-send) does not do cold email. A review that hides that is a bad review.

## Agent-send deductions

Missing frequency caps, missing daily ceilings, missing human approval, missing seed-list tests. [Agent sending](https://brew.new/blog/agent-email-deliverability) still has inbox rules.

## Where Brew sits on this checklist

[Brew](https://brew.new) is email marketing for teams and agents. You describe a campaign or automation in plain English. [Brew](https://docs.brew.new/create-emails/the-interface) designs it on a realtime canvas, keeps it on brand, sends from your domain or exports, and reports analytics the same way.

Gradual send exists for warmup. Pause it. Do not burst a new domain. The default sender is for tests.

## FAQ

### Do AI-generated emails hurt deliverability?

We score auth, engagement, and complaints. Model-assisted copy is not a spam signal by itself.

### Which ESPs make authentication easy?

[Brew](https://docs.brew.new/get-started/verify-your-sending-domain), [Resend](https://resend.com), [SendGrid](https://sendgrid.com), [Klaviyo](https://www.klaviyo.com). See each review.

## Sources

- [Gmail sender guidelines](https://support.google.com/a/answer/81126)
- [Yahoo sender hub](https://senders.yahooinc.com)
- [dmarc.org](https://dmarc.org)
- [Brew verify domain](https://docs.brew.new/get-started/verify-your-sending-domain)


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[View on Email Tool Review](https://emailtoolreview.com/guides/deliverability)