What Is an MX Record?
An MX (Mail Exchange) record is a DNS entry that specifies which mail servers are responsible for receiving email for a domain, and in what priority order. When someone sends a message to an address at your domain, the sending server looks up your MX records to know where to deliver it. Without correct MX records, incoming email cannot reach your inbox, making them essential for any business that uses email at its own domain.
- Full name
- Mail Exchange record
- Purpose
- Routes incoming email to the right mail servers
- Priority
- Lower number = higher priority (tried first)
- Defined in
- DNS standards (IETF RFC 1035 / 5321)
What is an MX record? #
An MX, or Mail Exchange record, is the DNS entry that tells the internet where to deliver email for your domain. When you use an address like [email protected], the mail servers that accept messages for yourbusiness.com are named in your MX records. A sending mail server that wants to deliver a message looks up your domain's MX records, finds the designated mail servers, and hands off the message to the highest-priority one available. MX records point to hostnames (which then resolve via A records to IP addresses), and each carries a priority number that sets the order servers are tried. Every domain that receives email at its own name needs correct MX records; get them wrong and incoming mail bounces or disappears. Because email is mission-critical for local businesses, MX records deserve careful handling. They live on your domain's nameservers alongside your other DNS records, see /wiki/what-is-a-nameserver, and we manage them for clients through /services/domains-dns-email.
How do MX records work? #
Email delivery follows a defined sequence built on MX records. When someone sends a message to an address at your domain, their mail server queries DNS for your domain's MX records. DNS returns a list of mail server hostnames, each with a priority number. The sending server attempts delivery to the server with the lowest priority number first, since lower means higher priority, and if that server is unavailable, it falls back to the next one in the list. Once it reaches an available mail server, it resolves that hostname to an IP address via its A record and delivers the message, see /wiki/what-is-an-a-record. The receiving mail system then places the message in the right mailbox. This design provides both routing and redundancy: multiple MX records with different priorities let mail keep flowing even if your primary mail server is temporarily down. Understanding this flow explains why priority ordering matters and why at least one working MX record is non-negotiable for receiving email.
What is MX record priority? #
Every MX record includes a priority value, a number that determines the order in which sending servers try your mail servers. The rule is counterintuitive: lower numbers mean higher priority. A record with priority 10 is tried before one with priority 20. This lets you designate a primary mail server and one or more backups: if the primary (lowest number) is unreachable, senders automatically try the next-lowest, and so on. If two MX records share the same priority, senders may distribute mail between them, a simple form of load sharing. For most small businesses using a hosted email provider like Google Workspace or Microsoft 365, the provider supplies a specific set of MX records with predefined priorities that you enter exactly as given. Changing or misordering those values can disrupt delivery. The priority system is what gives email its resilience, ensuring messages find an available server rather than failing on the first busy or offline one.
Why are MX records important for local businesses? #
For a local business, email at your own domain, like [email protected], signals professionalism and keeps you in control of your communications. MX records are what make that email work, so if they are missing or misconfigured, customer inquiries, appointment requests, and order confirmations simply never arrive. A dentist who cannot receive booking emails or a contractor missing quote requests loses real revenue, often without realizing why. MX problems are especially dangerous because they can be silent: your website works fine, so nothing seems wrong, yet incoming mail is quietly failing. This is also why moving hosts or changing nameservers is risky, if MX records are not carried over correctly, email breaks even as the site keeps loading, see /wiki/what-is-a-nameserver. Because the stakes are high, we treat email records as a first-class part of every domain and migration project, verifying that mail flows correctly, through /services/domains-dns-email, and we check deliverability with /tools/email-deliverability-checker.
MX records vs email authentication records #
MX records handle where incoming email goes, but they are only part of a healthy email setup. Separate DNS records govern whether your outgoing email is trusted. SPF, DKIM, and DMARC records, all stored as TXT records, tell receiving servers which servers are allowed to send mail for your domain and how to verify messages, protecting against spoofing and improving deliverability, see /wiki/what-is-a-txt-record. It is entirely possible to have correct MX records, so you receive mail, yet weak or missing authentication records, so your outgoing mail lands in spam. Many businesses discover this only when customers say their emails go unanswered because replies were filtered. A complete email configuration therefore pairs correct MX records with properly set SPF, DKIM, and DMARC. We configure the full picture, incoming routing and outgoing authentication, so both directions work, and diagnose problems using /tools/email-deliverability-checker, which flags missing or misconfigured records before they cost you business.
Common MX record mistakes #
Several avoidable errors break email. The most common during a host or DNS change is failing to copy MX records to the new provider, so incoming mail stops even though the website works, see /wiki/what-is-a-nameserver. Entering a provider's MX records with wrong priorities or typos in the hostnames misroutes or drops messages. Placing a CNAME on the domain name that also needs MX records breaks mail, because a CNAME cannot coexist with other records, see /wiki/what-is-a-cname-record. Leaving old MX records in place after switching email providers can send mail to a defunct server. Forgetting that MX changes take time to propagate leads to premature panic, see /wiki/what-is-dns-propagation. Finally, ignoring SPF, DKIM, and DMARC means outgoing mail suffers even when MX is correct. The safeguard is careful, verified configuration: enter records exactly as the provider specifies, remove stale entries, and confirm both sending and receiving work, which we do on every project.
How do you set up MX records? #
You configure MX records wherever your domain's DNS is managed, at your registrar, host, or DNS provider, in the DNS or zone editor. Your email provider, whether that is Google Workspace, Microsoft 365, or another service, supplies the exact MX hostnames and priority values to use. You create one MX record per server the provider lists, entering the mail server hostname and its priority number, and set a TTL. It is critical to enter these exactly as given and to remove any old MX records from a previous provider so mail is not misrouted. After saving, allow time for propagation, then send test messages in both directions to confirm delivery, see /wiki/what-is-dns-propagation. Because email downtime is costly and easy to cause, we handle MX setup for clients precisely, coordinating it with any hosting or nameserver change so mail never drops, through /services/domains-dns-email, and verify the result with /tools/email-deliverability-checker before considering the job done.
MX records and switching email providers #
Changing email providers, say moving from your web host's built-in mail to Google Workspace or Microsoft 365, revolves around updating MX records. The new provider gives you a set of MX records to add, and once those take effect, incoming mail routes to the new system. The delicate part is timing: because propagation is gradual, mail may briefly arrive at both the old and new systems during the transition, so you keep the old mailbox reachable until the switch fully completes, see /wiki/what-is-dns-propagation. You also update SPF and DKIM records for the new provider so outgoing mail stays authenticated, see /wiki/what-is-a-txt-record. Done carelessly, a provider switch can lose messages; done properly, it is seamless. We plan email migrations to avoid gaps, lowering TTLs beforehand, coordinating the cutover, and verifying delivery on both sides, as part of /services/website-migrations and /services/domains-dns-email, so the business keeps receiving every message throughout.
How do you check and troubleshoot MX records? #
When email problems strike, MX records are an early thing to inspect. You can look up a domain's current MX records with a DNS query tool or an online MX checker, which shows the listed mail servers and their priorities, letting you confirm they match what your email provider specifies. If incoming mail is failing, verify the MX records exist, point to the correct provider, have sensible priorities, and are set on the authoritative nameservers, see /wiki/what-is-a-nameserver. If outgoing mail is landing in spam, the problem is usually authentication rather than MX, so check SPF, DKIM, and DMARC, see /wiki/what-is-a-txt-record. Remember that recent changes may still be propagating. For a quick, business-friendly check of whether your email is set up to deliver reliably, our /tools/email-deliverability-checker reviews the key records and flags issues in plain language. When something is wrong, we diagnose and fix it as part of /services/domains-dns-email, restoring mail flow quickly.
FAQ
What does an MX record do?
An MX record tells sending mail servers which servers receive email for your domain, and in what priority order. When someone emails an address at your domain, their server looks up your MX records to know where to deliver the message. Without correct MX records, incoming email cannot reach your inbox.
What does MX record priority mean?
Priority is a number that sets the order sending servers try your mail servers, and lower numbers mean higher priority. A record with priority 10 is tried before one with priority 20, so you can designate a primary mail server and backups. Email providers supply the exact priorities to use.
Why did my email stop working after changing hosts?
Most likely your MX records were not carried over to the new DNS provider, so incoming mail has nowhere to go, even though the website works. Email failures after a host or nameserver change are common and silent. We coordinate MX records during every migration to prevent this, see /services/website-migrations.
Are MX records the same as SPF and DKIM?
No. MX records route incoming email, while SPF, DKIM, and DMARC (stored as TXT records) authenticate outgoing email so it is trusted and not marked as spam. You can receive mail correctly yet have outgoing mail filtered if authentication is missing. A complete setup needs both, see /wiki/what-is-a-txt-record.
How do I set up MX records for Google Workspace or Microsoft 365?
Your provider supplies the exact MX hostnames and priority values. You enter them in your domain's DNS editor, one record per listed server, remove any old MX records, and allow time to propagate. We handle this precisely for clients and verify delivery with /tools/email-deliverability-checker through /services/domains-dns-email.
How long do MX record changes take?
MX changes can take from a few minutes to 48 hours to take effect everywhere, depending on TTL and caching, a process called DNS propagation. During a provider switch, mail may briefly reach both old and new systems, so keep the old mailbox available until the change completes, see /wiki/what-is-dns-propagation.
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