Best Practices How Feedback Loops and Bounce Management Work (and Why They Matter for Transactional Email) By MailChannels | 4 minute read Deliverability isn’t just about getting emails sent, it’s about making sure they’re received, engaged with, and not marked as spam. Two of the most overlooked yet essential tools in any successful email infrastructure are feedback loops (FBLs) and bounce management. Together, they help you maintain list hygiene, protect your sender reputation, and ensure critical transactional emails, like password resets, receipts, and alerts, land in the inbox. In this blog, we’ll break down how both feedback loops and bounce handling work, and why they should be part of every transactional email setup. What Are Feedback Loops? A feedback loop is a mechanism that allows mailbox providers (like Yahoo, AOL, and Outlook) to notify senders when a user reports their email as spam. When a recipient hits the “Report Spam” button: The mailbox provider sends a report back to the sender (via the ESP or MTA) This alert allows the sender to remove or suppress that address from future sends For transactional email, spam complaints can signal deeper issues, like confusing content, incorrect targeting, or spoofed messages. Even though these emails are expected, users might still flag them if the email looks suspicious or if they didn’t recognize the sender. Why FBLs matter: They help you quickly detect and remove problematic addresses They protect your sender reputation by reducing repeat complaints They offer insight into email content or branding that might be triggering user mistrust What Is Bounce Management? A bounce happens when an email fails to reach the recipient’s inbox. Bounces come in two main types: 1. Hard Bounces These are permanent failures—like when an email address doesn’t exist or the domain is invalid. Examples: user@nonexistentdomain.com bob@company.com after the company shuts down Hard bounces indicate that your data is outdated or inaccurate. 2. Soft Bounces These are temporary issues, like a full inbox, a downed server, or a message that’s too large. While soft bounces might resolve on their own, repeated soft bounces should be treated with caution. Why bounce handling matters: High bounce rates damage your domain and IP reputation Repeatedly sending to invalid addresses can trigger spam filters or blocklists Transactional emails must reach valid users without delay. Poor bounce handling leads to failed logins, lost receipts, and frustrated users Best Practices for Feedback Loop and Bounce Management To keep your infrastructure clean and trustworthy: ✅ Subscribe to all available feedback loops from major mailbox providers ✅ Automatically suppress complaint addresses from future sends ✅ Remove hard bounces immediately from your list or database ✅ Monitor soft bounces and suppress addresses after repeated failures ✅ Tag and log bounce reasons for better diagnostics and reporting ✅ Use structured response handling to parse SMTP error codes effectively Your ESP or email infrastructure should help automate most of this. But it’s up to you to interpret the signals and act on them. How MailChannels Helps MailChannels automatically handles bounce classification and FBL processing under the hood. That means: You don’t need to manually parse bounce codes Complaint addresses are automatically suppressed from future deliveries You gain access to detailed logs to audit deliverability trends over time This lets you focus on building your application, not babysitting your email infrastructure. Final Thoughts Feedback loops and bounce management are critical components of email deliverability, especially for transactional email. They help you: Protect your sender reputation Reduce unnecessary sending to bad addresses Quickly act on user feedback and deliverability issues Want an email platform that handles all this for you? Start sending with MailChannels and let our infrastructure take care of the heavy lifting—so your emails always land where they should.