In Office 365 administrators can invoke the managed folder assistant by using the start-ManagedFolderAssistance command.
PS C:\> Start-ManagedFolderAssistant email@example.com
This week I had a customer present with an issue where the invocation of the managed folder assistance was failing with a generic RPC error.
“The call to Mailbox Assistance Service on server: ‘NAME’ failed. Error from RPC is –2147220989”
When this error is encountered subsequent retries of the same command can be successful.
The error can sometimes occur as portions of mailboxes are being initialized within the service. For example - if a secondary archive is being provisioned off a main archive.
As a potential workaround to this issue the primary mailbox GUID can be specified in the start-ManagedFolderAssistant command.
get-mailboxLocation –user firstname.lastname@example.org | fl mailboxGuid,mailboxLocationType
MailboxGuid : aace1f4e-5181-4855-a0c7-466f1fe2f1d1
MailboxLocationType : Primary
MailboxGuid : c2098d94-d55b-4a06-9b52-d485c54e9a19
MailboxLocationType : MainArchive
This command will dump the mailbox types and GUID of all mailboxes associated with a user.
From the list we can locate the primary mailbox and the mailbox GUID. Using this mailbox GUID we can invoke the managed folder assistance.
PS C:\> Start-ManagedFolderAssistant aace1f4e-5181-4855-a0c7-466f1fe2f1d1
When utilizing the GUID we can minimize the change that any initialization process does not cause the command to fail.