Warm-up your cold email inbox
Warmbox is an email warm-up and deliverability product. It says it connects a mailbox, runs automated warm-up interactions, and reports inbox reputation and deliverability.
| Plan | Price | Included | Notable |
|---|---|---|---|
| Solo | $15/month | 1 inbox warm-up; 50 emails/day 1 member | Premium support |
| Start-up | $69/month | 3 inbox warm-ups; 250 emails/day 3 team members | Premium support |
| Growth | $139/month | 6 inbox warm-ups; 500 emails/day 6 team members | Enterprise support |
| Team | Contact Us | — | Custom sending volumes |
Checked 2026-08-08 against their pricing page. Vendors change pricing without notice.
Warmbox automates mailbox warm-up activity intended to improve sender reputation before cold-email campaigns.
Sales and marketing teams operating cold-email campaigns that need to warm multiple sending inboxes and monitor delivery.
Teams that need a sales-engagement platform or a contact database should look elsewhere: the documented workflow is mailbox connection, warm-up scheduling, and deliverability tracking. Teams with more than six inboxes need a custom Team arrangement rather than a listed plan.
No curated rival set covers this tool yet, so these are simply other tools in the same architectural layer and product form. Treat it as a starting point, not a shortlist.
It says it sends and interacts with email automatically, including replies and moving messages out of spam.
The product lists SMTP plus Google and Outlook OAuth, and its integration page names providers such as Amazon SES and SendGrid.
Yes. The confirmed API reference documents bearer-token authentication, inbox management, warm-up control, stats, and webhooks.
Solo is listed at $15 per month for one inbox and 50 emails per day.
Yes. The API reference documents webhook events for mailbox lifecycle changes.
This page tells you whether Warmbox fits. Cheetah builds and runs the system it goes into — enrichment, sequencing, CRM and the joins between them.
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