Why does it say Marked as spam?

Nothing went wrong with the email. It reached them, and they chose Report spam in their mail app. Their mail provider passed that on, and Jounce marked them Complained and stopped sending to them. Everyone else got the email as usual.

Where it shows

Their row on Audience reads Complained, and their page’s Activity list has the line Marked as spam. The send it came from counts it under Spam complaints on its results page. The Emails tab on Analytics adds complaints up across a period.

What one complaint means for your sending

One complaint on its own never brings up the banner at the top of the app, and never pauses sending. For the person who complained, it’s final: Jounce never emails them again.

Complaints add up, though. Mail providers watch how often a sender’s emails are marked as spam. Past a limit they publish, they can start filing that sender’s emails as spam for everyone.

Jounce watches the same thing for your workspace. Once a send draws more than one complaint, its results page can say they ran high, in a line under its numbers. The banner at the top of the app can follow. See Sending warnings and pauses and Why does Analytics say complaints are high?.

Note Gmail doesn’t pass its readers’ spam reports on to Jounce. A Gmail reader who reports your email doesn’t turn Complained. If they unsubscribe at the same time, they turn Unsubscribed.

It can’t be undone

Nothing in Jounce lifts a spam complaint, even one made by mistake. Coming back after an unsubscribe, a bounce, or a complaint says what a form signup or a new address does for them.

Keep complaints rare

• Send only to people who asked for your emails. A list you imported needs each person’s permission. See The permission statement.
• Leave the unsubscribe link where it is. Jounce writes one at the bottom of every email, and a reader who can find it uses it instead of Report spam. See The unsubscribe link and page.
• Send at the pace you promised when they signed up, from a name they’ll recognize.