Recently I configured a new Office 365 E3 tenant for my lab environment and one of the domains I use (and had in mind for configuring Federation) was exchangelabs.nl.
When adding a domain to a tenant Microsoft has to verify if you’re the owner of the domain being added and this is achieved by you adding a TXT record to public DNS. Microsoft checks for this TXT and thus knows you’re the one and only owner.
After adding the TXT record the verification wizard failed with the following error:
Can’t verify domain
Exchangelabs.nl was already added to a different Office 365 account exchangelabs.onmicrosoft.com.
Sign in to that account as ad admin, and remove domain <domain>. Then come back here and try adding <domain> to this account again.
If you can’t sign in to exchangelabs.onmicrosoft.com as an admin, try resetting your admin password. Continue reading Can’t verify domain