What Is an MX Record? Definition, Example and How to Check

An MX records (the settings that tell the internet where to deliver email for your domain) (mail exchanger record) is a DNS entry that tells sending mail servers which server accepts email for your domain. When someone writes to you@yourdomain.com, their mail server looks up the MX record for yourdomain.com and delivers the message to the host it names. Without a valid MX record, inbound email has nowhere to go and bounces.

Quick summary

• Lower number = tried first. Priority 10 is tried before priority 20.
• Two records with the same priority are load-balanced at random.
• A single MX records (the settings that tell the internet where to deliver email for your domain) with priority 10 is completely normal for a small business; you do not need a backup MX.
• Do not set the same host at two priorities. It adds nothing and confuses some DNS panels.
• Open a terminal and run nslookup -type=MX (Mail Exchanger — where incoming email is delivered) yourdomain.com (Windows) or dig mx yourdomain.com (macOS, Linux).

How an MX record works

Every email delivery starts with a DNS query. The sending server asks the DNS system for the MX records of the recipient domain, receives one or more hostnames with a priority number, and connects to the lowest-priority host first on port 25. If that host is unreachable it moves to the next one. The MX record never contains an IP address directly; it names a hostname, and that hostname must have its own A or AAAA record so the sender can resolve it.

Example MX record

This is the exact MX records (the settings that tell the internet where to deliver email for your domain) OquMail asks you to publish. The host (sometimes labelled Name) is @ or left blank, meaning the root of your domain. The priority is 10, and the value is the mail host.

Type:      MX
Host:      @
Value:     mail.oqumail.com
Priority:  10
TTL:       3600

What the priority number means

• Lower number = tried first. Priority 10 is tried before priority 20.
• Two records with the same priority are load-balanced at random.
• A single MX records (the settings that tell the internet where to deliver email for your domain) with priority 10 is completely normal for a small business; you do not need a backup MX.
• Do not set the same host at two priorities. It adds nothing and confuses some DNS panels.

How to check your MX record

1. Open a terminal and run nslookup -type=MX (Mail Exchanger — where incoming email is delivered) yourdomain.com (Windows) or dig mx yourdomain.com (macOS, Linux).
2. You should see one line ending in mail.oqumail.com with preference 10.
3. Online, use MXToolbox or Google Admin Toolbox Dig and enter your domain.
4. In the OquMail dashboard, open your domain and press Check DNS; the MX row turns green when the record matches.

Common MX record mistakes

• Leaving an old MX records (the settings that tell the internet where to deliver email for your domain) from a previous host in place. Senders may deliver to the old server and mail seems to vanish.
• Typing a trailing dot or a stray space, for example "mail.oqumail.com " with a space at the end.
• Putting the MX on www or mail instead of the root @. Mail for you@yourdomain.com uses the root domain.
• Entering an IP address as the value. MX values must be hostnames.
• Enabling a Cloudflare proxy (orange cloud) on the A record of a hostname used by MX. Mail hosts must be DNS-only.

MX records and OquMail setup

When you add a domain to OquMail, the dashboard shows the MX records (the settings that tell the internet where to deliver email for your domain) above along with SPF, DKIM and DMARC values. Paste them at your registrar or DNS host, then press Check DNS. OquMail verifies each record live, so you know within minutes whether the MX record is correct. Once it is, every mailbox you create on that domain (up to 15 on the free plan) starts receiving mail immediately.

Common questions

Does changing my MX record affect my website?

No. MX records only control where email is delivered. Your website is controlled by A, AAAA and CNAME records. You can host your site anywhere and your email with OquMail on the same domain.

How long does an MX change take?

Most resolvers pick up the new record within an hour if your TTL is 3600 or lower. During the switch, some senders may still deliver to the old host, so keep the old mailbox reachable for a day.

Can I have MX records for a subdomain?

Yes. Set the host to the subdomain label (for example support) and mail for anyone@support.yourdomain.com will route to that MX. Most small businesses only need the root record.