Install-CsMirrorDatabase fails with SQL Service Domain Account in Internet-style format

Found an interesting gotcha with another Time2Market engineer today. When running the Install-CsMirrorDatabase command we ran into the following error.

“Mirroring cannot be setup unless SQL server service runs under a network service account, virtual account, local system account or a domain account.”

We knew the SQL Service account was a domain account already so I suggested a change from the format of "user at domain.com" to domain\user.

With that simple change the command ran successfully.