Once an email account has been delegated to you (or once you have been granted access), you can begin accessing that account from your own account. To do so, complete the following steps:
Log in to your Google Mail account.
Click your account photo or the circle with your first initial (located in the upper-right corner of the page).
From the drop-down menu, select the desired delegated account. A new window or tab will open, displaying the delegated account.