Rooms list - Exchange reference ids

When rooms are provisioned to Exchange, corresponding ID are tracked in the field 'Exchange IDs'.

The content is laid out with one line pr. room - line contains a combination of the email of the room and the Exchange GUID separated by the pipe "|" character.

You can create the recreate the field content using PowerShell

foreach ($item in (get-mailbox -RecipientTypeDetails "RoomMailbox" -ResultSize Unlimited |
where {$_.Name.StartsWith("Workspace-XX") } |
select PrimarySmtpAddress, ExternalDirectoryObjectId)
)
{
write-host "$($item.PrimarySmtpAddress)|$($item.ExternalDirectoryObjectId)"

}

[e-mail]|8eb75969-f8d3-496a-9cb8-340cbd84fb23
[e-mail]|4b07982a-7877-4410-8874-3bf012d5b388
[e-mail]|43ab4bf0-7945-4713-887f-eeb15e9b50cd
[e-mail]|5ddfc4ce-fa0a-4b94-9ffe-f243325af09e