Category
Email Deliverability
Key features
Automated warm-up interactions
Private network of 35,000+ inboxes
AI-written realistic emails
01 — Overview
What is
Warmbox
Warmbox is an email warm-up tool that improves sender reputation before and during cold email campaigns. It sends realistic emails from your inbox to a private network of over 35,000 inboxes, opens them, moves them out of spam, marks them important and replies, which builds trust with email providers. Dashboards track inbox reputation, spam scores, blacklists and DNS setup so outbound teams can keep campaigns out of spam.
02 — Who it’s for
Ideal Customer Profile
Sales and marketing teams that send cold email, from startups to enterprises, and agencies managing many client inboxes. The site says over 5,000 companies use it.
03 — Capabilities
Key Features
Automated warm-up interactions
Private network of 35,000+ inboxes
AI-written realistic emails
Custom warm-up schedules
Spam score monitoring
Blacklist and DNS checker
Multi-account for agencies
05 — Similar tools
Alternatives
06 — FAQ
Frequently Asked Questions
What is Warmbox used for?
Warmbox warms up email inboxes so cold outreach lands in the inbox instead of spam, by generating positive interactions that raise your sender reputation.
How does Warmbox work?
After you connect an inbox, Warmbox sends emails to its private network, opens them, removes them from spam, flags them and replies, then reports on your reputation over time.
Which email providers does Warmbox support?
It supports Gmail and Google Workspace, Outlook and Microsoft 365, Yahoo, iCloud, AOL, Yandex, Zoho, SendGrid, Brevo (Sendinblue), Mailgun, Amazon SES and any SMTP inbox.
Can agencies use Warmbox for clients?
Yes. Warmbox supports multiple inboxes, multi-account management for agencies and team members.