Delegated access to a Gmail account must be initiated from the owner of the email account.
You can perform the following actions on behalf of the person whose inbox you manage. (Check all that apply)
Send New Messages
Respond to Messages
Send and Receive Chat Messages
Manage Messages through Deleting, Labels, Archive, and Filters
Use Offline Gmail
By default, messages you send on behalf of the delegated mailbox owner will display the owner's name and yours.
To make emails you send on behalf of the delegated mailbox owner appear as being directly from the owner, you must setup the following in your settings.
Delegated alternate email address
Add another email address you own
Contacts are automatically delegated to you to use and manage once Gmail has been delegated.