Sending to an address that bounces hard, or one that filed a spam complaint, damages sender reputation for every Pendulum merchant on the shared sending domain. Pendulum suppresses these automatically so a bad address doesn't keep eroding deliverability.
When Pendulum auto-suppresses
- Hard bounce.The recipient's mail server returns a permanent failure (mailbox doesn't exist, domain doesn't exist, etc.). Postmark reports this back, Pendulum marks the address suppressed for that shop, and future reminders to that address are skipped.
- Spam complaint.The recipient clicks “Report spam” in their mail client. Postmark forwards the complaint via a feedback loop. Pendulum suppresses the address immediately.
Soft bounces (mailbox full, server temporarily down) do NOT trigger suppression. Pendulum will retry on the next reminder step.
Where suppressions show up
The Suppressions tab in the Pendulum app lists every suppressed address for your shop, with the reason (hard bounce or spam complaint) and the timestamp.
If 10 or more addresses get suppressed within a 30-day window, a warning banner appears on the home dashboard linking to the Suppressions tab. That's a signal worth checking: either you imported a bad list, or something about your sending pattern is generating complaints.
Manually unsuppressing
If you know the address is good (typo on a Shopify customer record, complaint filed by mistake), click Remove on the row in the Suppressions tab. Pendulum will resume sending to that address immediately.
Effect on the reminder cron and manual sends
Both the daily cron and the manual Send reminder button check the suppression list before firing. Manual sends to suppressed addresses return an error with the suppression reason instead of sending.
Related
Reminder cadence covers the schedule itself. Verified sender lets you send from your own domain, which decouples your deliverability from the shared Pendulum sending domain.