Scenario: You have a large dataset that you want to use a Do-While Loop with a Paging system to separate the data into smaller data sets. In this example, I will use a Do-While loop to set a roleassignmentpolicy against may mailboxes:

Solution: Run the following commands

Collect the Mailboxes

$mbx = get-mailbox -resultsize unlimited | where RoleAssignmentPolicy -ne “PolicyWithNoEmailForward”

Create the Page Variables

$total_Count = $mbx.count
$Sleep = 60 #in seconds
$page = 10 #the amount of records you want to go through per set
$page_Count = $page #The amount the page will increase

Buffer for DoWhile Loop

$mbx | Select -first $page | %{
$N = $_.name
“Setting RoleAssignmentPolicy on Mbx: $N”
Set-mailbox $n -roleassignmentPolicy “PolicyWithNoEmailForward”
}

Run the DoWhile Loop

Do{

#Run through the first set of Mailboxes
$mbx | Select -first $page -skip $page | %{
    $N = $_.name
    "Setting RoleAssignmentPolicy on Mbx: $N" 
    Set-mailbox $n -roleassignmentPolicy "PolicyWithNoEmailForward"
  }

#Display a separator between each set
 "

  Next"

#Increase the Page and SKip Count
  $Page = $page + $page_Count

#Sleep Duration
  Sleep $Sleep

} While($Page -lt $Total_Count)