The future of mailbox warmups is peer-to-peer
A few weeks ago, I warmed up several dozen mailboxes — purchased directly from Google Workspace — using one of the well-known warmup platforms (you know the duo). After four weeks, the dashboard showed a 100% inbox rate. So I ran my own test, sending to my personal Gmail accounts. A lot of the emails landed in spam.
Confused, I tested several accounts on EmailGuard. Most were sitting around 50% deliverability.
I posted here asking for help. The advice was clear: ditch the automated warmup and warm them up manually. I did — painfully — and after one to two weeks, deliverability climbed back toward 100%.
Since then, I've seen the same story pop up on this sub more than a few times.
That experience got me rethinking the whole warmup industry. Cold email tooling is fundamentally built for agencies. At agency scale, you can afford premium services, premium IP pools, and the deliverability that comes with them. Anyone running one to a few dozen mailboxes — solo founders, small teams, indie senders — falls into a gap where existing tools have cracks everywhere.
For senders in that gap, I think peer-to-peer warmup matters. And not the P2P you're probably thinking of — I mean warmup driven by real user behavior, not bots talking to bots.
Here's the part I keep coming back to: most "premium" warmup services aren't really premium. At best they mimic conversational threads, but we don't actually know whether Google or Microsoft inspects content — and both have been quietly tightening spam detection year over year while warmup tools have barely changed. Worse, every one of them sends via API or SMTP, which providers can detect directly. Real humans don't send their email through API or SMTP.
So what would a genuinely premium warmup look like? Web-based activity. Residential or business IPs. A limited number of accounts per IP. Only web-based P2P checks all three boxes.
That's why I built ThawingFox — a browser extension that does P2P warmup through the actual Gmail and Outlook web interfaces. It automates the tedious parts (sending, reading, replying, pulling from spam) so you can either warm up your own mailboxes or join the P2P network and warm up with other real users.
The extension is just the tool. The bigger goal is a community of senders who care about deliverability and want to help each other get there.
30-second demo on the landing page: https://thawingfox.com Discord (extended trial + find warmup buddies): https://discord.gg/kmNc5GTp