The mailbox database is temporarily unavailable. Cannot open mailbox

If one of the following errors occurs when you are attempting to restore

Microsoft Exchange Online data in a Cloud (Microsoft Office 365) backup set:

"The server cannot service this request right now. Try again later."

"The mailbox database is temporarily unavailable. Cannot open mailbox."

Do the following:

1. Attempt the restore activity at a later time.

2. If the error still occurs, increase the value of the "Miscellaneous"

advanced parameter "Office365RequestRetry" and reattempt the restore activity.

3. If the error still occurs, increase the value of the "Miscellaneous"

advanced parameter "Office365RequestRetry" and reattempt the restore activity

at a later time.

IMPORTANT: The duration of restore activities will be exponentially lengthened

for each Microsoft Exchange item with each additional retry allowed by the

advanced parameter "Office365RequestRetry".