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Email issues often involve more than one DNS record, but the MX record is the piece most business owners need to understand first. This article focuses on mail routing and the practical questions around business email. It stays separate from SPF and from general DNS propagation because those topics solve different parts of the email setup problem.
An MX record tells the internet where email for your domain should be delivered. If someone sends a message to you@yourdomain.co.uk, the sender’s mail system looks up the domain’s MX record to find the mail server responsible for receiving it.
For business owners, that means the MX record is one of the most important DNS settings for email. If it is wrong, outdated, or missing, incoming mail may fail or arrive somewhere unexpected.
The MX record does not store the email itself. It simply points to the mail server or mail service that should handle delivery for the domain.
That is why you can think of it as a routing instruction. The record says, in effect, “send mail here.”
Depending on your provider, the MX target may be:
The exact format varies by provider, so always follow the instructions they give you.
If your MX record is wrong, senders may not be able to deliver email to your domain. They might get a bounce, a delay, or a silent failure depending on the receiving setup and mail policy.
This matters especially when:
MX records handle routing, but they do not guarantee good deliverability on their own. Business email usually also relies on:
Those records help receiving mail systems decide whether a message is legitimate. So an MX record can be correct while email still lands in spam or is rejected for other reasons.
| Part | What it means | Why it matters |
|---|---|---|
| Priority | The order mail servers are tried | Lower numbers are usually tried first |
| Target host | The mail server hostname | It must exist and accept mail |
| Domain | The domain you are configuring | Make sure you are editing the live zone |
| Multiple entries | Fallback routing | Can improve resilience if set correctly |
Some domains use more than one MX record. The mail system will usually try the lowest-priority number first, then move to the next if needed.
This gives a fallback path if the primary mail server is unavailable. However, the real behaviour depends on the mail systems involved, and not every provider uses or needs the same setup.
If you see multiple MX entries, do not assume they are duplicates. They may be intentionally ordered for priority and resilience.
Usually the MX target is wrong, missing, or still pointing at the old provider.
A resolver may still be caching the old record, or the new provider has not fully accepted the change.
MX may be fine, but SPF, DKIM, DMARC, or sender reputation may be broken.
Different services or subdomains may be using different DNS records.
You will usually care about MX records in one of these cases:
In each case, the MX record must match the provider’s published mail hostnames exactly. A small typo can stop mail from arriving.
The most common problems are:
Another frequent issue is assuming that the MX target should be the same as the website hostname. Often it is not. Mail and web usually live on different infrastructure.
The MX record decides where mail goes. It does not decide whether the message looks trustworthy to the receiving mailbox. That is why MX problems and spam problems can look similar but need different checks.
If the domain is the business address, the MX record is the post room instruction. It tells senders where to drop the mail once they have found your address.
The record does not make the letters readable, secure, or spam-free. It only makes sure the delivery route exists. Other DNS records and mail settings handle authentication and reputation.
Be careful if you are moving mail for a live company. A bad MX change can interrupt incoming messages for customers, suppliers, or internal staff.
Before switching:
That reduces the chance of mail arriving before the destination is ready.
Many people assume that if a website works, email should work too. That is not safe.
A domain can have:
Those layers are independent. A website change does not automatically update email, and an email migration does not automatically update the website.