How do I change the sender name or let guests reply to me?

Open Manage → Settings → Email. Choose the sender name you want guests to recognize. Emails still include via Cut the Cake in the sender line.

To receive replies at the host's address, enable the reply-to-host option. It is off by default. Turning it on discloses that address to the people receiving those emails, and an email already sent cannot be taken back.

These controls are available to the host and co-hosts. Other event roles may be able to read the settings without changing them.