How many email accounts can I add on 4th Office? Francesca Baglietto 18 August 2017 15:19 Updated Follow On 4th Office, you can add up to 4 accounts on the desktop app and an infinite number on the iOS app. Related articles How can I remove my email account from 4th Office? How does Muted work? How do I add multiple email accounts? Why can't I add my email account? Problem with the iPhone / iPad app? Comments 0 comments Please sign in to leave a comment.