Bounces and spam complaints — what they cost you
The two numbers mailbox providers judge you on.
Almost everything about deliverability comes down to two numbers. Both are on your Analytics, and both are worth watching more than open rate.
Bounces
| Means | We | |
|---|---|---|
| Hard | The mailbox doesn’t exist | Stop mailing it, permanently |
| Soft | Full mailbox, server busy — temporary | Keep trying; nothing changes |
A high hard-bounce rate tells providers you’re mailing a list you didn’t collect or haven’t maintained — both are spam signals, regardless of what you actually sent.
This is why imports check every domain before accepting an address: the cheapest bounce is one that never happens.
Complaints cost far more
A complaint is worth roughly a hundred unsubscribes
Gmail’s threshold is 0.3% — three per thousand. Past it, everything you send gets filtered, not just the campaign that caused it. Recovery takes weeks of clean sending.
Someone pressing “report spam” is usually not accusing you of fraud. They’ve forgotten subscribing, or couldn’t find the unsubscribe link, and the spam button was nearer. That’s why the fixes are mostly about recognition and ease rather than content.
We stop sending before it gets that far
If your rates cross thresholds set below the providers’ own, sending pauses across your account — campaigns and automations alike.
It reads as heavy-handed in the moment. The alternative is discovering the problem when Gmail starts filtering everything you send, which takes far longer to undo. A halted send refunds its unsent portion.
Getting back to healthy
- Stop mailing the segment that caused it. Usually a list that hadn’t been mailed in a long time, or one that didn’t come from your own signups.
- Mail your most engaged people for a while. Recent openers and clickers — a segment on engagement does it in one rule.
- Remove the never-engaged. Someone who hasn’t opened anything in a year is far likelier to complain than to buy.
- Send more regularly, not less. Long gaps produce complaints because people forget you.
Common issues
Sending has been paused on my account
Look at your recent bounce and complaint rates in Analytics. Then get in touch with what you sent and to whom — that context is what moves it along.
Lots of bounces on a list I just imported
An old list. The import already refused undeliverable domains, so what bounced was addresses that used to work. Mail the engaged part and let the rest go.
Complaints from people who definitely signed up
Recognition, almost always. Make sure your From name is your business name, and that the email looks like what they expected when they subscribed.
FAQs
What's a healthy rate?+
Under 2% bounces and well under 0.1% complaints. Under 0.5% bounces on a list you collected yourself is normal.
Do bounces cost me credit?+
The send is charged, since the message was genuinely attempted. What costs more is the reputation, which is why suppression is automatic afterwards.
Can I see who complained?+
No — providers don’t identify them, and their status is changed automatically so they’re never mailed again. You can see the count per campaign, which is the actionable part.