What this symptom usually tells you
Email commonly fails after a nameserver move because the new DNS zone was built for the website and did not include the previous MX and authentication records. The website can be completely healthy while senders have no valid mail route for the domain.
Evidence that narrows the cause
Use the live diagnostic to test the exact hostname involved. For this problem, the highest-value evidence is below. Treat each result as one piece of the business-email DNS and mail authentication diagnosis rather than as a standalone health score.
- Check current MX — Read the public MX priorities and targets, then verify that each target itself resolves. A visible MX record is not enough if its mail hostname is broken.
- Identify provider — Verify identify provider from the public Internet and compare it with the value the responsible provider says should be live.
- Restore SPF/DKIM/DMARC — Inspect the single public v=spf1 policy, validate its terms and count DNS-query-causing mechanisms; duplicate policies or excessive lookups can invalidate SPF.
Record the current state before editing
Before changing business-email DNS and mail authentication settings, save the exact public values for check current MX, identify provider, restore SPF/DKIM/DMARC and note which hostname or mail path is failing. This creates a rollback point and prevents a later resolver cache, provider dashboard or unrelated working record from being mistaken for the original cause. Change one evidence-backed setting at a time, then compare the same signals again.
Safest repair path
Identify the actual mail provider, retrieve its current MX values and publish them at the new authoritative DNS provider. Restore SPF, DKIM and DMARC separately using the values for the same tenant/account. Do not copy obsolete records from a provider that is no longer used.
How to confirm this specific repair
The MX checker should identify the intended provider and every MX target should resolve. SPF should be a single valid policy, the configured DKIM selector should resolve, and DMARC should parse correctly. Then perform real inbound/outbound mail tests after DNS is public.
A common wrong turn
Do not point MX to the new web host unless the mailbox service genuinely moved there. Nameservers control DNS; they do not require the website and email to use the same company.
When to escalate with evidence
If these public checks match the provider's current documented configuration but the service still fails, give support the exact hostname, the observed business-email DNS and mail authentication result, a timestamp, and the failing network or message path. That separates a provider-side incident from a DNS change that has not actually become authoritative.
Technical references
These primary standards and provider documents are used to verify the behavior described on this page. Provider dashboards can change, so use the current official value for tenant-specific DNS records rather than copying an example from another account.