Email Marketing

The Email Deliverability Checklist for 2026

Authentication, list hygiene and sending habits that keep your emails out of spam — a checklist you can work through in an afternoon.

Great copy is worthless if it lands in spam. Since Gmail and Yahoo tightened their rules for bulk senders in 2024, authentication and low complaint rates are no longer optional. Work through this checklist once, then review it every quarter.

Authentication (do this first)

  • Send from your own domain, never a free address like @gmail.com.
  • SPF — publish a record that authorises your email platform to send for your domain.
  • DKIM — enable signing in your platform and add the DNS records it gives you.
  • DMARC — start with a monitoring policy (p=none), read the reports, then tighten over time.
  • Align your domains so the visible From domain matches the authenticated domain.

Most good platforms, including Brevo, MailerLite and ActiveCampaign, walk you through these steps.

Unsubscribes and complaints

  • Include a visible unsubscribe link in every marketing email.
  • Support one-click unsubscribe (your platform's list-unsubscribe header) and process requests quickly.
  • Keep your spam complaint rate as low as possible — Google advises staying well under 0.3%, and aiming much lower.

List hygiene

  • Use confirmed (double) opt-in for new subscribers where practical.
  • Never buy or rent lists.
  • Remove hard bounces automatically.
  • Run a re-engagement campaign for subscribers inactive for 90–180 days, then suppress those who still don't respond.

Sending habits

  • Warm up new domains gradually rather than blasting your whole list on day one.
  • Keep a consistent schedule so subscribers expect you.
  • Segment: send the most relevant message to the people most likely to engage.
  • Avoid spammy patterns: all caps subject lines, misleading "Re:" prefixes, link shorteners.

Content checks before every send

  1. Plain-text version included
  2. Images have alt text and the email still makes sense without them
  3. Links point to your own domain where possible
  4. A clear reason why the reader is receiving the email

Monitor

  • Register your domain with Google Postmaster Tools to watch reputation and spam rate.
  • Track opens cautiously (privacy features inflate them); clicks and replies are better health signals.

Deliverability is a habit, not a setting. Get the foundations right, keep your list clean, and the inbox will follow.

Choosing a platform? Read How to Choose Email Marketing Software.

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