So We had a shared mailbox that was originally opened in Finland and as such the inbox was named postilaatikkoon and sent items was named Lähetetyt.
So I thought I’d jump into OWA and change the language there, well it turns out that has nothing to do with Folder names.
So after some research I found I could use:
But the mailbox is shared so doesn’t have a enabled user to logon with so I found this Exchange PowerShell command:
set-MailboxRegionalConfiguration -id "Mailbox Name" -LocalizeDefaultFolderName:$true -Language en-GB