Campaign in cooldown mode
Campaigns auto-enter cooldown when a safety threshold is exceeded. This protects your sender reputation. The trigger is your bounce rate: once a campaign has enough sends to judge fairly, a bounce rate above 5% (the default threshold) stops it. If you set the optional reply-rate floor on a campaign, a reply rate far below that floor can pause it too.
Cooldown does not lift on its own. The campaign stays paused until you fix the cause and click Resume — and resuming starts a fresh safety baseline, so from then on the campaign is judged on what it sends after you resumed rather than on the bounces that paused it.
To fix: 1) Check your prospect list quality — remove invalid or catch-all email addresses. 2) Run the list through the Email Verifier before you resume; this is the single most effective way to bring a bounce rate down. 3) Verify your DNS records (SPF, DKIM, DMARC) are correct. 4) Lower your daily sending volume. Then open the campaign and click Resume.
Spam complaints are not a trigger. When a recipient reports your email as spam, that report goes to their own mailbox provider — your campaigns send from your own connected mailbox, so it never reaches WarmySender and we cannot count complaints or pause on them. Watch your complaint rate in Google Postmaster Tools (Gmail) or Microsoft SNDS (Outlook).
The campaign status will show 'Cooldown' in orange on your Campaigns page.
Full explainer with the arithmetic worked through, the list-cleaning steps in order, and how to set a stricter limit: warmysender.com/documentation/why-did-my-campaign-pause-for-bounces