DNS
4 articles tagged DNS.
Email migration cutover checklist: DNS TTLs, MX switch and day one
A practical cutover runbook for moving a domain's mail to Exchange Online: lower TTLs early, switch MX and Autodiscover safely, and support users on day one.
Fix DKIM CnameMissing in Microsoft 365 and enable signing for your domain
Why Microsoft 365 reports CnameMissing when you enable DKIM, how to publish the exact selector CNAME records, and how to confirm the domain signs mail.
Outlook Autodiscover problems with Microsoft 365: DNS checks and fixes
Fix Outlook profiles that can't find an Exchange Online mailbox: check the Autodiscover CNAME, root domain responses, cached URLs, registry and Group Policy settings.
SPF, DKIM and DMARC for Microsoft 365: set up, test and reach p=reject
Publish SPF, enable DKIM signing and roll DMARC out from p=none to p=reject for Microsoft 365 custom domains, with DNS examples, PowerShell commands and header checks.