FAQs
Why can't the retro sync resubscribe people in Campaign Monitor?
If you've run a retro sync hoping to resubscribe contacts who previously unsubscribed from a Campaign Monitor list, you may have noticed it doesn't work. This is a known limitation in the integration, and it applies to both types of retro sync. Understanding why can save a lot of troubleshooting time.
The Solution
There are two retro sync paths in the integration, and both have the same limitation when it comes to resubscribing.
Custom Mapping Retro Sync
When you run a retro sync from the custom field mappings screen, it only processes Subscription records in Salesforce that are currently in an Active state. Anyone whose subscription has been marked as unsubscribed, bounced, or deleted is excluded entirely and will not be sent to Campaign Monitor. Even in edge cases where a contact is still Active in Salesforce but already unsubscribed in Campaign Monitor (an out-of-sync scenario), the integration sends the import with resubscribe set to false, meaning Campaign Monitor will not re-activate them.
Subscriber Rule Retrospective Run
When you run a retrospective on a subscriber rule, the same limitation applies. The retrospective always sends with resubscribe set to false, even if the subscriber rule itself has the Resubscribe option enabled. This is a known inconsistency: during a normal, trigger-driven sync the rule's Resubscribe setting is honoured correctly, but during a retrospective run that setting is ignored and resubscribe is hardcoded to off.
What you can do instead
Campaign Monitor does not allow bulk resubscription via API as a safety measure to protect against spam and comply with consent regulations. If you need to resubscribe someone, the options are:
- The subscriber opts back in themselves via a Campaign Monitor sign-up form or preference centre
- You manually update their status directly in Campaign Monitor if you have a legitimate reason and the appropriate permissions
- You use a Campaign Monitor Journey or a re-engagement campaign to invite them to opt back in
