The Email Tracking tab of your Company Settings shows you a record of every email sent through ARIVE by the company.
This tab also exists in Branch Settings (where it shows emails from all users in the branch), and User Settings (where it only shows your emails).
Click on emails to open them. There is a search bar in the upper right corner.
The status in the rightmost column will tell you if an email sent successfully. If one fails, mouseover the info icon to see the error message (invalid_grant means the sender of this email needs to reconnect their email integration).
You can also look at the email history of a specific loan file from the Email Logs tab of the action menu in a loan file.