MX Record

What is an MX Record?

An MX record, or Mail Exchange record, is a type of DNS record that tells the internet which mail servers are responsible for accepting email messages sent to a specific domain. When someone sends an email to you@yourdomain.com, the sending server performs a DNS lookup for the MX records of yourdomain.com to find out where to deliver the message. Without valid MX records, email sent to your domain has nowhere to go and will bounce.

How MX Records Work

MX records are published in your domain’s DNS zone alongside other records like A records, CNAME records, and TXT records. Each MX record contains two pieces of information: a priority value (also called preference) and the hostname of a mail server. The priority value is a number where lower values indicate higher priority. When multiple MX records exist for a domain, the sending server tries the highest-priority (lowest number) server first and falls back to lower-priority servers if the primary is unavailable.

For example, a domain using Google Workspace might have MX records pointing to aspmx.l.google.com at priority 1, alt1.aspmx.l.google.com at priority 5, and additional fallback servers at priorities 10, 20, and 30. This ensures email delivery even if the primary Google mail server is temporarily unreachable.

MX Records in Cold Email Infrastructure

For cold email operations, MX records are part of the foundational DNS configuration that must be in place before any sending begins. The MX records tell receivers where your domain receives mail, which is important even for domains primarily used for outbound sending. Reply handling, bounce processing, and deliverability feedback all depend on having correctly configured MX records.

When setting up new domains for cold email, the MX records must match the email provider you are using. If your mailboxes are on Google Workspace, your MX records must point to Google’s mail servers. If you are using Microsoft 365, they must point to Microsoft’s servers. Mismatched MX records will cause delivery failures for incoming mail and can also raise red flags with spam filters that cross-check DNS consistency.

Common MX Record Issues

The most frequent MX record problem is misconfiguration during initial setup. Copying records incorrectly, using the wrong priority values, or forgetting to remove old MX records from a previous provider can all cause delivery failures. Another common issue is DNS propagation delay — after changing MX records, it can take up to 48 hours for the changes to propagate globally, though most updates take effect within an hour. Always verify MX records using a DNS lookup tool after making changes, and wait for propagation to complete before sending email from the domain.

Outspun & MX Records

With Outspun’s mailbox provisioning, MX records are configured automatically when we set up your Google Workspace or Microsoft 365 accounts. The entire DNS stack — MX, SPF, DKIM, DMARC — is handled as part of our managed infrastructure, eliminating the most common setup errors.