Here’s one I’ve seen a couple of times recently, and initially thought it was a one off. When you run the Hybrid Configuration Wizard and reach the Domain Proof of Ownership page you’ll see a table containing the TXT records you need to add to confirm you own the domain.
If you’re not sure what these are (and why you need to register them after already going through a similar process for the Office 365 custom domain itself) allow me to briefly explain. These records are used for Federated Sharing. This is different to AD FS, and relates to Exchange Free/Busy and Calendar sharing across an Exchange-organization’s boundaries. You confirm the domain with a TXT record which the Microsoft Federation Gateway will check and, once it’s confirmed will trust the certificate your Exchange organization presents.
Anyway – what do you do if you get stuck at this stage? Well (and you’ll find these now outdated instructions on one of my pre-HCW articles from a few years ago) you just need to use the Get-FederatedDomainProof cmdlet to retrieve the TXT record for the domain:
For example, Get-FederatedDomainProof -DomainName lisajanedesigns.co.uk
We can then add the TXT record into DNS as normal, then once it has taken effect re-run the HCW. The table will still be blank, but you can safely continue through the Hybrid Configuration Wizard.