Wrong MX means lost mail
Incorrect or stale MX records send your incoming email to the wrong place — or nowhere — and customers get bounces.
Free Email Tool
MX Checker
MX records are the signpost that tells the internet where to deliver mail for your domain. Get them wrong and incoming email bounces or vanishes. This guide explains the records, their priority and the routing to look for — and a specialist will check yours for you, free.
Information:
Automated checker coming soon
What this tool checks
What a healthy MX setup looks like.
An MX check reads the records that route your incoming mail. These are the parts that decide whether email reaches your mailboxes.
-
MX records exist
Your domain should publish at least one MX record pointing at a real, reachable mail server.
-
Priorities are sensible
Lower numbers are tried first. A clear primary and backup priority order avoids delivery confusion.
-
Hostnames resolve
Each MX hostname must resolve to a valid address — a typo or dead host means mail cannot be delivered.
-
They match your provider
Your MX records should point at the platform you actually use (Microsoft 365, Google Workspace, your own server), not a stale one.
-
No leftover or duplicate records
Old MX records from a previous host can misroute mail or split delivery in ways that lose messages.
-
A backup path where needed
For resilience, a correctly configured secondary MX can hold mail if your primary is briefly unreachable.
Why it matters
MX records decide if mail arrives at all.
SPF, DKIM and DMARC protect outgoing mail; MX records govern incoming. When they are wrong, the failure is loud — mail simply does not arrive.
They break after migrations
A change of platform that forgets the MX records is one of the most common causes of mail suddenly stopping.
They affect resilience
Sensible priorities and a backup path keep mail flowing through brief outages instead of bouncing straight back.
Common problems
The MX mistakes we see most.
Most MX issues come from change — a migration, a host switch, a half-finished edit. A check catches them before mail goes missing.
-
Pointing at the old provider
After a migration, MX records still route to the previous platform, so new mail lands in an abandoned mailbox.
-
A typo in the hostname
One wrong character means the MX hostname does not resolve, and delivery fails for everyone trying to reach you.
-
Conflicting priorities
Misordered or duplicated priorities cause inconsistent routing, with some mail delivered and some bounced.
-
No MX record at all
Without an MX record, senders fall back to risky defaults or simply cannot deliver to your domain.
Preview the checker
Check a domain's MX records
This is a preview of the automated MX checker we are building. It does not run a live lookup or store anything you type.
Coming soon
Automated checking is on its way. A human audit is available now.
We are building instant, automated checkers as part of our Email Operations Center roadmap. Until then, a specialist will run this check by hand as part of a free Email Audit — and explain what it means for your business in plain English, with no jargon and no obligation.
- A real specialist reviews your setup — not an automated guess.
- Plain-English findings and the next step that actually matters.
- Free, with no obligation — we work alongside your existing IT.
Questions
Answers, in plain English.
What is an MX record, in plain English?
An MX (Mail Exchanger) record is a DNS entry that tells other mail servers which server to deliver email to for your domain. It is the address the rest of the internet uses to reach your inbox.
What does MX priority mean?
When a domain has more than one MX record, each carries a priority number. Senders try the lowest number first, then the next, and so on. This lets you set a primary mail server and one or more backups.
Why did my mail stop arriving after a migration?
Very often the MX records were never updated to point at the new platform, so incoming mail still routes to the old, abandoned server. Updating MX records correctly is a core part of a clean migration — which is exactly what we handle.
Do I need a backup MX record?
For many businesses the modern cloud platforms provide enough resilience on their own. A backup MX can help in specific self-hosted setups, but a misconfigured one can also cause problems — so it should be set up deliberately, not copied blindly.
Does this tool look up my MX records live?
Not yet — the automated checker is in development. This page explains MX records and what a healthy setup looks like, and the form is a preview that does not run a live lookup. For results today, request a free manual audit.
My incoming mail is bouncing — can you help?
Yes. Bouncing or missing incoming mail is usually a routing or DNS issue we can diagnose quickly. If it is urgent, request Emergency Email Support; otherwise a free audit will pinpoint the cause.