Email deliverability describes how reliably your legitimate messages reach recipients' inboxes, as opposed to landing in spam or being rejected outright. It is distinct from simple delivery: a message can be accepted by a server yet still be filtered away from the inbox.
Deliverability matters because email only has value if it is seen. Mailbox providers such as Gmail and Microsoft weigh many signals, but a large share are within your control through DNS and authentication. Properly aligned SPF and DKIM, plus a DMARC policy, prove your mail is genuine and not forged.
The main technical levers are: valid authentication that aligns with the visible From domain, good sending-IP and domain reputation, low complaint and bounce rates, and clean DNS. Poor authentication is a frequent cause of mail being throttled or junked, and being listed on a DNSBL can block delivery entirely.
To check and improve deliverability, confirm SPF, DKIM and DMARC pass and align, review DMARC aggregate reports to find unauthenticated senders, keep lists clean, and verify your sending IPs are not blacklisted. Reaching DMARC enforcement also strengthens reputation with major providers.
Check it on your domain
- Email Deliverability Score: score a domain's email authentication out of 100 with a shareable badge.
- DMARC Checker: look up and validate a domain's DMARC record and policy.
- Blacklist Checker: check a domain or IP against email blacklists.