Email Forwarding in Office 365
Before doing this, make sure you finish doing steps 1 & 2 indicated in this link https://breeneng.freshdesk.com/solution/articles/22000226724-terminating-it-personel or titled “Terminating IT Personnel” in our Freshdesk solutions.
After completing the steps in 1&2 of the link above, continue until the 3rd bullet in step no. 3. Before you ‘’Remove license” of the user’s Office 365, execute this:
a. Go to Office 365 admin center, select Groups > Shared Mailboxes.

b. If the user doesn’t have shared mailbox, click + Add a mailbox in the upper right and create a mailbox for the specific user. input the details required then click Add.

* If the user already has a shared mailbox, just click his/her name.
c. Click the user's name and his email details will show up. Go to Email Forwarding > Edit. Turn ON the 'Forward all email sent to this mailbox'. Input the forwarding address and click save.
*note that you can assign specific user or a group to receive his emails.

4. After doing so, send a test email to the previous user to see if it works well or the email has been forwarded to the assigned address you put in.
After successfully creating a shared mailbox, you can now remove the Office 365 license of the former user.