For context: I was running cold email campaigns across 4 mailboxes. Every warmup service I tried charged $29/mailbox/month. That's $116/mo before sending a single email.
So I spent 2 weeks building WarmInbox.
It does the same thing the big tools do: Connects to any mailbox via SMTP/IMAP Sends realistic emails to a pool of real accounts daily Opens them, replies 40% of the time Score goes from 0 100 over ~4 weeks
Most warmup tools charge $29/mailbox/month. WarmInbox gives you 3 mailboxes on the Starter plan for the same price — and 10 on Pro for $79.
Connects via SMTP/IMAP, sends realistic human-like emails daily between a pool of real accounts, marks them as read, replies 40% of the time. Warmup score goes from 0 to 100 over 4 weeks. Works with Gmail, Outlook, and any custom domain.
Free plan available — 1 mailbox, no credit card required.
