~ email guide

MX Priority Explained

MX records tell other mail servers where to deliver email for a domain. Each MX answer has a priority number, and lower numbers are preferred first.

How Priority Works

• The lowest priority value is tried first.
• Multiple records with the same priority can be used for load sharing.
• Higher priority records are fallback targets when preferred servers fail.

Common Mistakes

• Pointing MX directly to an IP address instead of a hostname.
• Leaving old provider MX records after a migration.
• Publishing MX targets that do not resolve with A or AAAA records.
• Forgetting related SPF, DKIM, and DMARC changes.

Good Check Order

Check MX first, then confirm the MX host resolves, then review SPF, DKIM, DMARC, and blacklist status if messages still fail.