What’s the difference between complaint feedback vs bounce feedback?

You open your deliverability report and see two different signals in red: a complaint rate above 0.1% and a bounce rate climbing past 5%. Both look bad. But they're telling you completely different things, and they hit your sender reputation in completely different ways.

Complaint feedback means a recipient got your email, opened it (or didn't), and clicked "This is spam." The message was delivered successfully. They just didn't want it. This signal comes back to you through a Feedback Loop (FBL), where the mailbox provider reports the complaint back to your ESP. Complaints are a direct trust signal. ISPs read them as evidence that your list doesn't want to hear from you, and that hits your reputation fast.

Bounce feedback means delivery failed before the message ever reached a human inbox. A hard bounce means the address doesn't exist. A soft bounce usually means the mailbox was full, or the receiving server was temporarily unavailable. Bounces tell ISPs that your list is dirty or poorly maintained. That's a different problem from complaints, but it still matters for your reputation over time.

So which one should you tackle first? In almost every case, complaints win. Here's why.

A complaint rate of 0.08% or higher starts moving the needle at Gmail and Outlook. Cross 0.3% and you're in serious territory. Mailbox providers treat complaints as a live signal about whether their users want your mail. Too many complaints and they start routing your campaigns to spam, throttling your sends, or blocking you outright. The damage can happen within days.

A 3% bounce rate is a real list hygiene issue, but it plays out more slowly. High bounce rates damage your IP and domain reputation over time, and can trigger blocks from certain providers. But you're not usually looking at an immediate reputation crisis the way you are with complaint spikes.

The fix for each is also different.

• Complaints: Suppress the address permanently and immediately. Don't wait. Then look upstream: where did these subscribers come from? Did they opt in clearly? Are you sending too frequently? The complaint is a symptom of a consent or relevance problem.
• Hard bounces: Remove them from your list right away. Continuing to send to invalid addresses signals to ISPs that you don't maintain your list. Your ESP may also suspend you if bounce rates stay high.
• Soft bounces: Monitor them. If an address soft bounces repeatedly over a few sends, treat it like a hard bounce and remove it.

One thing worth noting: Gmail doesn't share complaint data through a traditional FBL. You'd need Google Postmaster Tools to see your complaint rate there, and it shows domain-level data, not individual addresses. If you haven't set that up yet, it's worth doing.

If your list is overdue for a clean, we can take a look. RME Clean flags invalid, risky, and undeliverable addresses before they turn into bounce or complaint problems.