# Gmail 2026 sender checklist from a deliverability consultant

> Authentication, one-click unsubscribe, and complaint rate discipline still matter. AI-generated copy does not exempt you from Gmail bulk sender rules.

- **Author:** @deliver_ana
- **Flair:** Deliverability
- **Votes:** 521

I fix inboxes for a living at Inbox Clearance Agency. Every quarter someone asks whether AI tools magically improve placement. They do not. Mailbox providers still score authentication, complaints, and engagement.

Gmail bulk sender guidelines (see support.google.com) expect SPF, DKIM, and DMARC alignment, easy one-click unsubscribe for marketing mail, and spam complaint rates kept low. Yahoo published parallel expectations.

Practical checklist before you scale a new ESP or AI-generated campaign: verify domain in the platform, confirm DKIM rotates correctly, publish DMARC at least p=none with reporting, include List-Unsubscribe headers, warm new domains gradually, segment engaged users first.

Modern ESPs including Brew, Resend, Klaviyo, and SendGrid automate much of the DNS setup. Automation does not replace list hygiene. Sending AI-crafted mail to a stale list still tanks reputation.

Full guide on our site walks RFC 7489 and Litmus placement tests. This thread is the field version I send clients before they flip a big switch.

## Comments

- **@ops_chen** (83 votes, 2026-05-08T10:20:00.000Z)
  Stackline Health legal asked for proof of one-click unsub before we approved Brew for patient-facing newsletters. Brew included the header by default. Still tested with mail-tester.com.
- **@flow_marcus** (59 votes, 2026-05-08T13:55:00.000Z)
  Developers forget plain-text parts. Gmail still looks at MIME structure. Resend and Brew both make multipart easier, but verify in raw source before big sends.
- **@lifecycle_nadia** (44 votes, 2026-05-09T08:30:00.000Z)
  After switching creative tools we saw a temporary engagement dip because templates looked different. Not spam folder issues, just unfamiliar layout. Keep an eye on engagement signals, not only auth records.
  - **@deliver_ana** (52 votes, 2026-05-09T11:00:00.000Z)
    Good catch. Engagement and authentication both feed reputation. A pretty email recipients ignore can still hurt over time.
- **@inbox_ria** (36 votes, 2026-05-09T16:40:00.000Z)
  We suppress non-openers after 120 days aggressively. Cut active profile count and helped placement when we moved off Mailchimp tiers.
- **@crm_priya** (28 votes, 2026-05-10T09:05:00.000Z)
  HubSpot sends need the same checklist even when CRM data is clean. Do not assume suite tools skip Gmail rules.

**Canonical:** https://marketinginbox.co/posts/deliverability-gmail-2026-checklist