Cold email for SaaS onboarding. How we reduced churn by reaching out to inactive users
retention_ryan · 2026-03-18 · 1,430 views
This is not traditional cold outreach. We used cold email infrastructure and techniques to solve a retention problem, and it worked better than anything our marketing automation ever did.
The problem: Our SaaS product had a 30-day trial. About 40% of trial users stopped logging in after day 5. Our marketing automation (Brevo drip campaigns) was sending them "come back" emails, but those emails looked like marketing. Branded HTML templates, company logo in the header, tracking pixels, unsubscribe footer. They landed in the Promotions tab in Gmail or went straight to spam. The re-engagement rate from those automated emails was 2.1%.
The experiment: I set up 5 PuzzleInbox Google Workspace inboxes under a domain that matched our brand (similar to our main domain but separate). I connected them to Instantly and built a 3-email sequence targeting trial users who had not logged in for 3+ days.
The emails were plain text. No HTML. No tracking pixels. No images. They came from our customer success manager's name. The first email was 45 words: "Hey [first name], noticed you signed up for [product] a few days ago but haven't had a chance to explore it yet. Totally normal. Is there anything specific I can help you with to get started?" It read like a real person reaching out, because it basically was.
The results: Re-engagement rate jumped from 2.1% to 11.4%. That is a 5x improvement. 23% of re-engaged users converted to paid plans within their trial window. Monthly churn dropped from 8.2% to 5.7% over 3 months. The infrastructure cost was about $30/month (5 inboxes plus Instantly). The additional revenue from saved churn was roughly $4,200/month.
Why it worked: The emails looked like they came from a real person who cared. Because they did. Our CSM actually monitored replies and responded personally. The plain text format bypassed the Promotions tab and landed in the primary inbox. No tracking pixels meant better deliverability. The short, conversational tone felt like a colleague checking in, not a company trying to retain a number.
What we learned: Cold email infrastructure is not just for cold outreach. Any time you need an email to land in the primary inbox and feel personal, cold email techniques outperform marketing automation. We now use this approach for onboarding, re-engagement, renewal reminders, and NPS follow-ups. Each one uses plain text from a real person's inbox.