Bulk remove proxy addresses matching a pattern

aliases_remove_bulk.ps1

$mailboxes = Get-Mailbox | Select-Object Alias,ExchangeGuid,Emailaddresses
foreach ($mailbox in $mailboxes) {
 
    $aliases = $mailbox | select -ExpandProperty EmailAddresses | ? {$_.Split(":")[1] -notlike 'string*'}
    if ($aliases.Count -eq $mailbox.EmailAddresses.Count) {continue}
 
    if ($aliases | ? {$_ -cmatch "SMTP:"}) {
        $emailaddresses = $aliases
    }
    elseif (!$aliases) { $emailaddresses = $("SMTP:" + $mailbox.Alias + "@" + (Get-AcceptedDomain | ? {$_.Default -eq $true}).Name)  }
    else {
        $emailaddresses = ($aliases -join "," -replace "smtp:(?!.*smtp:)","SMTP:") -split ","
    }
    Set-Mailbox $mailbox.ExchangeGuid.ToString() -EmailAddresses $emailaddresses
}