Symptom:
(public)
If someone with an account on the submission website submits a paper on
behalf of an author, is there a way of ensuring that the author, instead of
the submitter, receives the e-mails which are sent our via the website?

Problem:
(public)
Solution:
(public)
Sure. In the contact section, just enter the author's email address
in the place slot for email. That will make sure that the email for
the submission goes to the author.