In older versions of Outlook you could access the Account Setting from the File | Account Settings options and then selecting the account and clicking Change.
From here you could manage all the server and other MORE settings.
In later 2016 versions this seem to have been removed and you need to access it via the Send/Receive dialogue box as follows:
In Outlook 2016
- Press Ctrl+Alt+S to open Send/Receive settings. ...
- Click Edit.
- Select the account.
- Click Account Properties to open the Internet Account Properties dialog.
From here you can access all the server and other settings, such as Outgoing Server and other tabs under the old MORE button.