Bounces, complaints and unsubscribes

Bounces, spam complaints and unsubscribes are the health check on your list. They reflect how your recipients feel about hearing from you, and they feed directly into your sender reputation. Send engaging content to people who want it and these numbers stay near zero; let them creep up and your delivery suffers. You'll find them as totals and percentages in each campaign report, and against individual contacts.

Bounces

A bounce is an email that couldn't be delivered, and there are two kinds:

• Hard bounce - the address doesn't exist (and perhaps never did). Hard bounces are removed from your list automatically, and a high rate can get an account suspended, so they matter.
• Soft bounce - a temporary problem, like a full inbox or a server issue. If a single address soft-bounces four times, it's removed from the list automatically.

Your report breaks bounces down by reason - full inbox, blocked, DNS failure and so on.

Bounce rate = total bounces / total number of people you sent to

Aim for 0% to 1%, and keep your hard bounce rate below 1%. Industry, list age and sending frequency all play a part - the more regularly you send, the lower each campaign's rate tends to be.

Unsubscribes

Unsubscribe rate = total unsubscribes / total number of people you sent to

Expect a few unsubscribes on every send - that's normal. The thing to watch is a sudden spike. And remember: an unsubscribe is far better for your reputation than a spam complaint, so always keep your unsubscribe link easy to find. Aim for under 1%.

Spam complaints

Complaint rate = total complaints / total emails sent to a given provider

When someone marks you as spam, they're permanently removed from your list. Aim for 0% to 0.1%, and never exceed 0.25% - that's one complaint in every 400 emails. Inbox providers watch this closely; consistently high complaints push your mail to junk or block it entirely.

Troubleshooting

Hard bounce rate above 1% - review where your list came from (bought lists bounce heavily), use double opt-in so addresses are verified at signup, validate your list before sending, and remove subscribers who haven't engaged in 6-12 months.

A spike in spam complaints - look at what changed in your content or frequency, make sure your unsubscribe link is obvious and working, and slow down before ramping send volume back up.

Soft bounces turning into hard bounces - watch the soft-bounce reasons, try resending at a different time, and check whether particular domains bounce consistently.

Unsubscribe link not working - test the unsubscribe link in preview, make sure the unsubscribe page is reachable, and enable one-click unsubscribe for a smoother experience.

If your bounce or complaint figures look wrong, open a support ticket.