TL;DR: An MX (Mail eXchange) record is a DNS record that tells other mail servers where to deliver email for your domain. Each MX has a priority number — lower is tried first. No MX (or a wrong one) means inbound mail bounces. Scan your domain free to confirm your MX and email security are set up right.
How MX records work
When someone emails [email protected], the sending server looks up your domain's MX records to find your
mail host (for example aspmx.l.google.com for Google Workspace). It then delivers the message there. Your MX
records point at your mail provider, which is often different from where your website is hosted.
MX priority explained
Each MX record has a preference number:
yourdomain.com. MX 10 mail1.provider.com.
yourdomain.com. MX 20 mail2.provider.com.Lower numbers are tried first. So 10 is the primary; 20 is a backup used only
if the primary is unreachable. Equal numbers share the load.
Common MX mistakes
- No MX record — inbound mail has nowhere to go and bounces.
- Pointing MX at an IP — MX must point to a hostname, not an IP address.
- Leftover old MX records after a provider migration, causing split or lost delivery.
- Forgetting the null MX on a domain that doesn't send or
receive — publish
0 .to declare it accepts no mail.
MX and your email security
MX gets your mail delivered, but it doesn't protect it — that's the job of SPF, DKIM and DMARC, plus MTA-STS for encrypted inbound transport. A complete setup needs both correct routing and authentication.
FAQ
How many MX records should I have?
As many as your provider lists — usually two to five, with priorities. Use exactly what your mail host documents.
Does changing MX cause downtime?
If done carefully, no. Add the new provider's MX before removing the old, and watch the TTL during the switch.
Can I check my MX records myself?
Yes — or scan your domain and we'll confirm your MX along with your email-security records.
Mail bouncing or not sure your routing is right? Scan your domain, then reply to your report — we're developers and we'll sort out your MX and authentication for you.