[ Quick answer ]
Email deliverability is the ability of your messages to reach the inbox instead of spam or being rejected. It depends on authentication (SPF, DKIM, DMARC), sender reputation, low complaint rates, clean lists and easy unsubscribe. Gmail and Yahoo now require all of these for bulk senders.
Key facts
- ›Gmail and Yahoo require SPF, DKIM and DMARC for senders of 5,000+ daily messages.
- ›Keep the spam complaint rate below 0.3%, ideally under 0.1%.
- ›Bulk marketing mail needs one-click unsubscribe (RFC 8058).
- ›Sending IPs need valid forward and reverse DNS.
- ›Blocklist listings and misaligned DMARC are common causes of spam placement.
Reviewed 2026-11-02 · EmailAuth research team
Deliverability is decided by the receiving provider, based on who you are (authentication), how you have behaved (reputation) and how recipients react (engagement and complaints).
Deliverability checklist
- 1
Authenticate
Pass SPF and DKIM, and publish DMARC aligned with your From domain.
- 2
Protect reputation
Keep complaint rates under 0.3%, remove bounces and inactive addresses, and warm up new IPs and domains.
- 3
Make leaving easy
Add one-click unsubscribe headers and honor requests within two days.
- 4
Check infrastructure
Valid reverse DNS on sending IPs, TLS, and no blocklist listings.
- 5
Monitor
Read DMARC reports and Google Postmaster Tools weekly.
Frequently asked questions
What is email deliverability?
The share of your sent messages that land in recipients' inboxes rather than spam folders or bounces.
How do I improve email deliverability?
Authenticate with SPF, DKIM and DMARC, remove inactive and invalid addresses, keep complaints low, add one-click unsubscribe, warm up new IPs and check blocklists.
How do I test email deliverability?
Check your authentication with a domain health scan, send to test inboxes and review headers with an email header analyzer, and monitor DMARC reports and Google Postmaster Tools.
What is a good email deliverability rate?
Most practitioners aim for 95% or more of messages delivered and a high inbox placement rate, with complaints under 0.1%.
Why are my emails going to spam?
Usually missing or failing SPF, DKIM or DMARC, a blocklisted IP, high complaint rates or content that looks like spam.
[ Email deliverability guide ]
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