MX Record: What It Is and Why It Matters for Your Business

What Is an MX Record

An MX record—short for Mail Exchange record—is a type of DNS entry that tells the internet where to deliver email addressed to your domain. It works a bit like a set of delivery instructions: when someone sends a message to you@yourcompany.com, other email servers check these records to find out which mail server is responsible for receiving messages on your behalf.

Each MX record includes two key pieces of information: a priority number and a target hostname (such as mail.yourcompany.com or aspmx.l.google.com for Google Workspace). The priority is a numeric value—lower numbers indicate a more preferred server. The target is the hostname of the server that actually accepts incoming mail. You can have multiple MX records with different priorities, providing a backup if your primary mail server goes offline.

Real-World Analogy

Think of MX records like a directory posted in the lobby of a large office building. When a courier arrives with a package, they look at the directory to see which floor and department should receive it. Without that listing, the courier can’t complete the delivery and the package gets returned. Similarly, without a correct MX record, email senders won’t know which server accepts mail for your domain, and messages will bounce.

How MX Records Work

When an email is sent to an address at your domain, the sending server performs a DNS lookup specifically for MX records. It receives a list of all your domain’s MX entries, sorted by their priority values. The server then attempts to connect to the target hostname that has the lowest priority number (meaning it’s the most preferred). If that connection fails—perhaps the server is unreachable or under maintenance—the sending server automatically tries the next lowest priority, and so on, until a successful delivery occurs or all options are exhausted.

For this mechanism to work, the target hostname must resolve to an actual IP address via an A or AAAA record. The MX record itself never directly contains an IP address; it always points to a hostname. This design gives you the flexibility to change the underlying server’s IP address without modifying your MX records, as long as the hostname’s A record is updated.

Once a server accepts the message, it stores the email or forwards it to your mailbox, depending on your configuration. The entire process takes place in seconds and is invisible to the sender—unless something is misconfigured, in which case they may get a bounce notification like "address not found" or "host unknown."

Why It Matters for Your Business

MX records are the foundation of reliable email delivery. If they are missing or incorrect, practically all mail sent to your domain will bounce back to the sender. This can mean losing customer inquiries, vendor invoices, password reset links, or even legal notices. For any business, that type of communication blackout directly hurts operations and brand trust.

Beyond simple delivery failures, misconfigured MX records can create security risks. An attacker who manages to add an unauthorized MX record with a high priority could intercept some or all of your incoming email—a technique often used in domain hijacking scenarios. Similarly, if your MX records still point to a retired email provider you no longer use, that provider’s server might accept and discard messages you never see.

Having properly set MX records ensures that every legitimate message reaches you, while also supporting business continuity through backup servers. As your company grows and switches email platforms, keeping these records current avoids embarrassing gaps that could make you appear unprofessional or unreachable.

Common Issues and Warning Signs

Problems with MX records often go unnoticed until you realize you’re not receiving expected emails. Business owners may hear from clients that their messages "bounced back," or discover their team hasn’t gotten any new leads through a website contact form. These symptoms almost always trace back to one of a handful of DNS misconfigurations.

A few common scenarios that a scan of your domain would uncover:

Any of these warning signs can seriously disrupt business communication. A quick diagnostic check can confirm whether your domain’s MX configuration is healthy.

Common Issues

No MX records found — Email delivery is impossible because no server is designated to accept mail for your domain. Any message sent to your address will bounce.

MX target hostname doesn’t resolve — The server name in your MX record cannot be translated to an IP address, often because the hostname was mis-typed or the corresponding A record was removed. Senders will see "host unknown" errors.

Only one MX record with no backup — A single point of failure. If that server ever goes offline for maintenance or an outage, all incoming mail is delayed or lost until it recovers.

Pointing to a retired email provider — Your MX records still list a server belonging to a service you no longer use, like an old hosting company. Mail is silently accepted and discarded, or rejected with obscure errors.

Wrong priority order — Your backup server has a lower (more preferred) number than your main server, causing mail to be routed to the less reliable system first. This can cause delays or misrouting of sensitive email.

How to Fix or Improve MX Records

The good news is that fixing MX records is entirely within your reach if you have access to your domain’s DNS settings. You don’t need to be a programmer or system administrator; you just need the correct values from your current email provider and a few minutes to log into your DNS management panel.

Here’s a straightforward process to audit and correct your MX records:

If you’d rather not dive into DNS settings manually, a free domain scan from TechSpy can automatically examine your MX records alongside other critical DNS entries that affect email security and deliverability. It takes less than a minute and gives you a clear, human-readable report highlighting any issues you need to address.

1Identify your DNS hosting provider—this is typically the company where you registered your domain (e.g., GoDaddy, Namecheap) or a separate DNS service. You’ll need the login credentials.

2Log into the DNS control panel or management console. Look for a section labeled "DNS Management," "Zone Editor," or "Advanced DNS."

3Locate the MX records area. You may see a list of existing entries with priority and target fields.

4Obtain the exact MX hostnames and priorities from your current email provider. For Microsoft 365, they use something like with priority 0. Google Workspace lists specific MX servers and priorities in their setup guide.

5Delete any outdated or incorrect MX entries. Be careful not to remove records that belong to your current email service unless you’re replacing them entirely.

6Add new MX records one at a time, entering the correct priority value and the hostname exactly as provided by your email service. Double-check for typos—a missing dot or extra letter can break delivery.

7Save the changes and allow time for DNS propagation. While updates often take effect within minutes, some DNS providers may take up to 24–48 hours for global distribution.

8Send test emails from an external account (like Gmail or Yahoo) to an address at your domain. Check both delivery and whether the email lands in your inbox or spam folder.