When sending email from a web app, using a "no reply" address can be detrimental to delivery rates and reputation. Email is about communication, which flows two ways, denying the chance for people to get in touch with real humans behind the product or site. This practice also risks inbox delivery rates and can hurt one's reputation by not allowing emails to be added to contacts, which improves delivery in some email clients like Gmail. In contrast, setting up a mailbox that actually works, even if it's just to browse occasionally, is still the best approach, especially for cases where people may try to reply to emails, such as with comment notifications.