Check the Cora app first
Your briefs are always available at cora.every.to even if the email was not delivered. If your brief is there but you did not receive the email, the issue is with email delivery rather than brief generation.
Check your email folders
If you are not receiving brief emails:
Check All Mail in Gmail - not just Inbox and Spam. Gmail can silently filter emails without showing them in Spam. Search for "from:cora.computer" in Gmail to find any filtered briefs.
Add the sender to your contacts - adding Cora to your Gmail contacts prevents future filtering.
Move the email to your inbox - if you find a brief in All Mail, moving it teaches Gmail to deliver future briefs there directly.
Brief delivery times
Briefs are sent on your schedule (morning and afternoon by default on weekdays). If a brief is more than 2 hours late, check the Cora app to see if it is already available there.
Multiple Gmail accounts
If you have connected more than one Gmail account, each has its own separate brief sent to a different email address. Make sure you are checking the inbox of the specific Gmail account you connected, and that you are viewing the right account in the Cora app using the account switcher in the top left.