To set up additional POP/IMAP accounts in Outlook 2016
In Outlook, choose the File tab.
Under Account Information, choose Add Account.
Use the Manual setup or additional server types option to set up your account
Choose Manual setup or additional server types > Next. 
Choose POP or IMAP > Next.
Enter the following information.
Your name and email address
Account type: IMAP
Incoming mail server
Outgoing mail server
User Name: This is your full email address
Password
Choose More Settings > Outgoing Server and check the box for My outgoing server (SMTP) requires authentication.
On the Advanced tab, enter the information you received from your email provider or from the POP and IMAP server name reference topic. The most common settings are below.
Incoming server (IMAP): 993
Use the following type of encrypted connection: SSL
Outgoing server (SMTP): 465 or 587
Use the following type of encrypted connection: SSL or TLS
Choose OK > Next > Finish.