Adding people to a safe senders list
If you find that e-mails you are expecting are going to your junk or spam mailbox instead of your inbox, you may be able to fix the problem by adding the senders to a safe senders list, also called a whitelist. Here are instructions for how to add people to a safe senders or whitelist using various e-mail systems.
Outlook (Mac):
Follow instructions for Office 365
G-mail:
https://www.lifewire.com/how-to-whitelist-a-sender-or-domain-in-gmail-1172106