Forum Discussion
DKIM CnameMissing for alderohotel.it stuck for 6 days - backend cache reset needed
DKIM for custom domain alderohotel.it has been stuck in CnameMissing status for 6 days despite correct CNAME records.
Tenant: alderotech (Microsoft 365)
CNAME records published on Aruba DNS:
- selector1._domainkey.alderohotel.it → selector1-alderohotel-it._domainkey.alderotech.w-v1.dkim.mail.microsoft.com
- selector2._domainkey.alderohotel.it → selector2-alderohotel-it._domainkey.alderotech.w-v1.dkim.mail.microsoft.com
Verified via PowerShell Resolve-DnsName: records resolve correctly.
Get-DkimSigningConfig -Identity alderohotel.it returns Status: CnameMissing.
Set-DkimSigningConfig -Enabled $true fails with CNAME validation error.
Microsoft support diagnostic tool also shows CnameMissing.
Requesting manual backend cache reset for DKIM signing config on alderohotel.it.
1 Reply
Hi, if the CNAME records resolve correctly from public DNS but Microsoft 365 still shows CnameMissing after several days, I would focus on DNS validation and then open a support case for backend refresh.
Things to double-check first:
1. Query both selectors from an external resolver, not only from your DNS provider panel.
2. Make sure the CNAME target exactly matches what Defender/Exchange admin center generated for that tenant.
3. Check for an extra dot, typo, wrong selector number, or old record cached at the authoritative DNS level.
4. Confirm there are no conflicting TXT records at the same selector names.
If all of that is correct after 24-48 hours, support can usually verify the backend state and refresh the DKIM validation. I would include screenshots plus public DNS lookup results in the ticket.
