Function Get-MailboxUsage {

    $mailboxuser = Read-Host "Please enter the mailbox to check or leave blank for all mailboxes"
    $getprohibitsendquota = Read-Host "Would you like to include max mailbox capacity? (Y/N)"

    if ($getprohibitsendquota -eq "Yes") {

            $SO_Params = @{
            Property = 'DisplayName, IsArchiveMailbox, ItemCount, TotalItemSize, ProhibitSendQuota'}}

    else {

            $SO_Params = @{
            Property = 'DisplayName, IsArchiveMailbox, ItemCount, TotalItemSize'}}

    if ($mailboxuser -eq '') {
            Get-Mailbox |
            Get-MailboxStatistics |
            Select-Object @SO_params |
            Format-Table –autosize}
    else {
            Get-Mailbox $mailboxuser |
            Get-MailboxStatistics |
            Select-Object @SO_Params |
            Format-Table –autosize}
    }