Single mail server
Check id: mx.single · fix effort: low
What it means
All your inbound mail depends on one server. Short outages are fine since senders retry for a day or two. If you're on Microsoft 365 or Google, their single MX is backed by redundant infrastructure and this is normal.
The technical detail
One MX host with no fallback. Hosted providers are redundant behind their single record, self-hosted setups may want a secondary.
How to fix it
- If your provider offers a secondary MX, add it.
- For hosted providers (Google/M365) a single MX record is normal and fine. their infrastructure is redundant behind it.
Does your domain have this problem?
Run a free scan, takes about ten seconds.