How to pull a list of all conference rooms in Exchange Online?

To pull the data you will first need to connect to Exchange Online Powershell. Instructions can be found here.

Next run these cmdlets to collect all the conference rooms.

get-mailbox -ResultSize unlimited |where {$_.recipientTypeDetails -eq "roomMailbox"}

This cmdlet below will get the same results above and export the Display name and Primary SMTP address to a text file.

get-mailbox -ResultSize unlimited |where {$_.recipientTypeDetails -eq "roomMailbox"} | Ft Displayname,PrimarySmtpAddress > Rooms.txt