How inbound mail follows MX records
A sending mail server looks up MX records, chooses the lowest-priority available target, then resolves that target to an address before opening an SMTP connection. A visible MX record does not prove the mail service is ready.
MX troubleshooting checklist
Check priority values, target hostnames, A or AAAA records, SMTP availability and mail-provider settings. An MX target should be a hostname rather than an IP address, and it should not be a CNAME.
Check real data now
Use the live IIPP tool to inspect the domain or IP address you are working with.
DNS Record Lookup →