Declining email open rates for campaigns using no-reply email addresses are driven by several interconnected factors. While no new specific email sending mandates exist, no-reply addresses negatively impact sender reputation by discouraging engagement and preventing valuable feedback loops, such as bounce messages and spam complaints. ISPs and email providers view these addresses as indicative of lower-quality email practices, potentially triggering spam filters and reducing deliverability. This, in turn, diminishes trust and disengages subscribers, ultimately harming open rates. Conversely, using valid, monitored reply addresses helps build trust, improve sender reputation, and enable better campaign tracking and performance.