All tools
DNS & Infrastructure
MX Lookup
Look up MX records for any domain. See priorities, hostnames, IPs, and detect missing or misconfigured records.
This tool is being wired up. The analyzer ships in the next build phase.
About this check
Look up MX records, priorities, and resolved IPs.
Frequently asked questions
- What does the MX Lookup actually check?
- Look up MX records, priorities, and resolved IPs.
- Is this really free?
- Yes. Every on.bo tool is free, no signup required, no rate-limit tricks.
- Do you store the data I check?
- We log minimal metadata to keep the service healthy. Lookups themselves are not retained beyond short-term caching.