WarmupInbox review: Automated email warmup and cold outreach tool for sender reputation.

What WarmupInbox does

Automates email warmup to build sender reputation and runs cold email sequences concurrently to maintain deliverability.

WarmupInbox is a deliverability platform that automatically builds sender reputation to help users achieve high inbox placement. The tool provides automated email warmup alongside cold email sequences, allowing users to scale their outreach without damaging their sender reputation. The sequences send from mailboxes that continue warming up simultaneously. Additionally, the platform monitors over 100 blacklists daily and automatically initiates a rescue process if an inbox is flagged. Users can also clean their contact lists using built-in email verification before launching campaigns and run A/B tests to compare two email versions, automatically applying the winning variant.

Pricing is structured on a per-inbox basis. The Freemium plan is free forever, requires no credit card, and supports unlimited inboxes, but it is limited to 15 warmup emails a week and basic reports. Paid tiers include the Basic plan at $15 per inbox per month ($180 billed yearly) for 75 warmup messages a day. The Pro plan costs $49 per inbox per month ($588 billed yearly) for 250 warmup messages a day, and the Max plan is $79 per inbox per month ($948 billed yearly) for 1,000 warmup messages a day. A 7-day free trial is available and only requires an email address to start.

• Automated email warmup
• Cold email sequences
• Blacklist monitoring
• A/B testing
• Email verification
• Developer API

Our take

WarmupInbox is designed for users who need to scale their cold email outreach while actively maintaining their sender reputation. By combining continuous automated warmup with cold email sequences, it ensures that sending domains remain healthy during active campaigns. It is a good fit for those who want built-in blacklist monitoring and list verification. However, it is not suitable for users seeking mobile or desktop applications, as it is strictly accessible via web and API.