What can I do to improve my email deliverability?

To reach the inbox consistently, you need to establish credibility as a sender and build a positive reputation with mailbox providers like Gmail and Outlook. Here’s how — and what Letterhead already handles for you.

Best practices

1. Obtain permission. Only send to people who actively subscribed. Letterhead sends a verification email to confirm each subscriber legitimately opted in.
2. Be transparent. Keep content relevant to the recipient and provide meaningful information in your Subject, From, and Reply-to headers.
3. Eliminate hard bounces. Invalid addresses should never receive future sends — Letterhead removes hard bounces for you automatically.
4. Stop sending to uninterested recipients. Consider removing or suppressing subscribers who haven’t opened or clicked recently (for example, in the last 30 days).
5. Authenticate your domain. DKIM should be set up and verified for your sending domain:
   • If you send from the @a.letterhead.email domain, no action is needed — it’s already configured.
   • If you set up a custom domain with Letterhead during onboarding, this was configured for you.
   • Letterhead also establishes custom bounce and tracking domains during onboarding.

Practices to avoid

• Sending without testing and proofreading.
• Concealing the sender’s identity or using deceptive subject lines.
• Hiding or ignoring unsubscribe links and requests.
• Purchasing email lists, particularly from untrustworthy sources.
• Selling your list to third parties without permission.

Going deeper

For a diagnostic look at why a specific send landed in spam, see Why Did My Email Go to Spam? For industry-standard guidance, review the M3AAWG Sender Best Common Practices.