Usually, your email box (Gmail, Outlook, etc.) will filter emails as SPAM and will block them from showing on your "INBOX."
They are often located in your "SPAM" or"JUNK EMAIL" folder.
If the email that we sent you is located in the "SPAM" folder (or "JUNK EMAIL), you can report the email as "Not Spam."
Here is an example using Gmail:
You can also try to refresh your mailbox by clicking the circular arrow: