# 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 (Editorial contributor (pen name))

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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Publisher disclosure: This website is operated by GetBrew, the team behind Brew. Coverage is based on public product documentation. Numeric scores and example scenarios, incidents and outcomes are illustrative editorial material, not verified customer evidence or measured research. Verify current capabilities and limits with each vendor.