i have asked my users to enable archiving on their outlook so the sizes of mailboxes on the server will reduce no to monitor this - is there a way to tun a cmdlet to show me ONLY the users with mailboxes larger than a specific size ? 1 GB or 512 MB for example

You can use the below cmd let: Get-Mailbox -resultsize unlimited | Get-MailboxStatistics | where {$_.TotalItemSize.Value.ToMB() -lt 512}

In addition, you can also try this cmdlet. Get-MailboxStatistics -Server <ServerIdParameter> | Where {$_.TotalItemSize -Gt 1GB} | Sort-Object -Property TotalItemSize -Descending | Format-Table DisplayName, TotalItemSize Hope helps. Noya Lau TechNet Community Support

thank you so much this is what i was looking for