What is an MX record and how does it relate to email delivery?
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An MX record (Mail Exchange record) is a DNS entry that tells the internet which mail server accepts incoming email for your domain. Without it, email sent to you@yourdomain.com has nowhere to go.
Here's the key distinction that trips people up: MX records are for receiving email. They don't affect your ability to send email. That's controlled by different DNS records (SPF, DKIM, DMARC). MX records tell other mail servers where to deliver messages addressed to your domain. SPF and friends tell other mail servers whether you're allowed to send on behalf of your domain.
So when When someone sends you an email, their mail server looks up your domain's MX record, finds the mail server address (something like mail.yourdomain.com or the IP of your email provider's server), and delivers the message there. If your MX record points to the wrong server, or doesn't exist, the sender gets a bounce message like "550 Host unknown" or "Domain not found."
Most email providers (Google Workspace, Microsoft 365, Zoho Mail) give you specific MX records to add when you set up your domain. For example, Google Workspace uses multiple MX records with priority numbers. The sending server tries the lowest priority number first, then falls back to higher numbers if that server is unavailable.
Still an MX record looks like this in your DNS settings:
- Type: MX
- Name/Host: @ (represents your root domain)
- Priority: 10
- Value/Points to: mail.yourprovider.com
Common mistakes: pointing your MX record to an old server after migrating email providers (your mail goes to the old provider and disappears), setting up MX for a subdomain but forgetting the root domain (info@company.com works, but hello@company.com bounces), or mixing MX records from two different providers (half your mail goes to Google, half to Microsoft, chaos ensues).
And if you're troubleshooting delivery issues and you're NOT receiving email, check your MX records first. If you're sending email and it's not arriving, MX records are not your problem. Look at SPF, DKIM, and your sender reputation instead.
Want to see what your MX records actually say? You can check them with our free Email Header Analyzer, or just ask our SOS hotline if something's not working.
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