This is just because the current user does not have the "Mailbox Import Export” management role assigned.
To give him the role with RoleGroup membership assignment :
1- Create a new RoleGroup:
[PS] C:\Windows\system32>New-RoleGroup "PST Rights"
2- Assign the pre-existing Exchange Server 2010 RBAC role “Mailbox Import Export” to this newly created group :
[PS] C:\Windows\system32>new-ManagementRoleAssignment -Role "Mailbox Import Export" -SecurityGroup "PST Rights"
3- Add the user who wants to use the Mailbox Import Export commandlets to the newly created rolegroup :
[PS] C:\Windows\system32>Add-RoleGroupMember "PST Rights" -Member Administrator
4- Restart the exchange management shell and now you’ll see these cmdlets
Note : You can use the ECP to create a Role Group, Assign Management Role( s ) and assign users to the newly created Role Group
Appendix : the list of cmdlets we have in the pre-existing “Mailbox Import Export” management Role
[PS] C:\Windows\system32>Get-ManagementRoleEntry "Mailbox Import Export\*" | ft -AutoSize
Name Parameters ---- ---------- Write-AdminAuditLog {Comment, Confirm, Debug, DomainController, ErrorAc Suspend-MailboxImportRequest {Confirm, Debug, DomainController, ErrorAction, Err Suspend-MailboxExportRequest {Confirm, Debug, DomainController, ErrorAction, Err Set-MailboxImportRequest {AcceptLargeDataLoss, BadItemLimit, BatchName, Conf Set-MailboxExportRequest {AcceptLargeDataLoss, BadItemLimit, BatchName, Conf Set-ADServerSettings {ConfigurationDomainController, Confirm, Debug, Err Search-Mailbox {Confirm, Debug, DeleteContent, DomainController, D Resume-MailboxImportRequest {Confirm, Debug, DomainController, ErrorAction, Err Resume-MailboxExportRequest {Confirm, Debug, DomainController, ErrorAction, Err Remove-MailboxImportRequest {Confirm, Debug, DomainController, ErrorAction, Err Remove-MailboxExportRequest {Confirm, Debug, DomainController, ErrorAction, Err New-MailboxImportRequest {AcceptLargeDataLoss, AssociatedMessagesCopyOption, New-MailboxExportRequest {AcceptLargeDataLoss, AssociatedMessagesCopyOption, Get-MailboxImportRequestStatistics {Debug, DomainController, ErrorAction, ErrorVariabl Get-MailboxImportRequest {BatchName, Database, Debug, DomainController, Erro Get-MailboxExportRequestStatistics {Debug, DomainController, ErrorAction, ErrorVariabl Get-MailboxExportRequest {BatchName, Database, Debug, DomainController, Erro Get-Mailbox {Anr, Credential, Debug, DomainController, ErrorAct