Why can't I use a "Do Not Reply" address?

The use of "Do Not Reply" addresses (e.g. donotreply@example.com), though quite prevalent, is not good practice. You can read more about why in our post: "Do Not Reply” Address? Don't Bother. When you discourage subscribers from replying to you, or don't provide them with a way to communicate with you, they may mark your messages as spam. This will ultimately affect your deliverability and sending in the future. You want to be accessible to your subscribers so you can address any issues they're experiencing with your messages. 

Although using your name helps build brand recognition and can make your messages more personal, if you don't want to use your name, then you should consider using an info@ or help@ domain-based email address. When you submit and verify the from address on the List Settings page in your account the system will check for a "Do Not Reply Address." If this type of email address is detected, you will be prompted with an error message.