A campaign that goes quiet without warning is one of the harder problems to diagnose — there's no error, no alert, just a contacts list that stops moving. We found and fixed the root causes of several stall patterns that could affect campaigns under heavy load.
What was happening
Two distinct problems could leave contacts waiting indefinitely for their next step:
Backlog starvation. In workspaces with large follow-up queues, the scheduler let existing follow-up work crowd out newly enrolled contacts. Fresh prospects sat waiting for a sending slot that never came, even when there was capacity available. The problem scaled with backlog size — the more follow-ups queued, the worse the starvation.
Strand-on-failure. A transient send failure — a brief network hiccup, a momentary mailbox error — could strand a campaign instead of scheduling a retry. The campaign looked active but was effectively frozen for affected contacts, with no indication anything had gone wrong.
What we fixed
- Follow-up backlogs no longer crowd out new campaign sends — the scheduler now balances fairly across both, so newly enrolled contacts get timely first emails regardless of queue depth.
- Transient failures retry automatically instead of stranding the campaign at the point of failure.
- Paused emails reactivate without colliding over sending slots when they resume.
- A watchdog now detects and recovers any campaign that does get stuck, so a stall can't persist indefinitely even if an edge case slips through.
Why it matters
Timing is a meaningful variable in cold outreach. A contact who should receive their first email on day one and their follow-up on day three converts differently than one who waits days longer than intended. Stalls compress your effective reply window and produce misleading campaign data — a sequence that appears to be underperforming may simply be behind schedule. These fixes keep your campaigns moving at the cadence you designed.
What to check
Nothing — recovery is automatic. If a campaign previously looked stuck, its status on the Campaigns page now reflects reality, and the campaign Logs tab shows every retry as it happens.
If you had campaigns that appeared active but weren't sending, check their logs now. You'll see where they stalled and confirm that sends have resumed. Any contacts that were waiting in a stalled state will be picked up in the next scheduling cycle automatically, without needing to be re-enrolled or touched manually. The sequence continues from where it left off — no steps are skipped and no duplicates are sent.