Email deliverability

Transactional email deliverability basics

Deliverability is not a switch you turn on. It is a set of habits: authenticate the domain, send mail people expect, handle bounces, avoid stale lists, and watch what mailbox providers do with your messages.

Verify a Domain Email API

Core checks

  • Use a verified sending domain, not a random From address.
  • Publish SPF, DKIM, and DMARC records.
  • Send wanted transactional email: login codes, receipts, alerts, and account updates.
  • Honor bounces and suppress invalid recipients.
  • Add List-Unsubscribe metadata where the message type should support it.

What zaSend handles

  • DNS record generation and verification
  • DKIM signing with per-domain keys
  • Bounce processing and suppression lists
  • List-Unsubscribe headers when unsubscribe URLs are supplied
  • Email logs and webhook events for debugging

Inbox placement is still earned

SPF, DKIM, and DMARC help mailbox providers trust that your domain authorized the message. They do not guarantee inbox placement. New domains and new sending infrastructure need steady, wanted email, low bounce rates, and low complaint rates over time.