A lists reply_to_address accepts only a single address.
The value in the list's
reply_to_address is parsed by
email.utils.parseadder into a display name and address to be added to the Reply-To: header being built for the message.
email.utils.parseadder returns only a single display name and address pair regardless of what the list's
reply_to_address contains. We should instead be parsing the list's
email.utils.getaddresses and adding all the pairs returned.