Last updated: January 2026
What Is Warmy?
Cold email outreach only works if your messages actually reach the primary inbox. Send from a new domain without preparation, and you'll likely land in spam—wasting time, damaging sender reputation, and burning through prospect lists. Warmy is a cloud platform designed to protect the metric that matters most: deliverability.
By simulating realistic human-like email conversations, repairing damaged domain reputation, and teaching mailbox providers (Gmail, Outlook, Yahoo) to trust your sending domain, Warmy keeps cold emails out of spam folders and in front of real prospects.
Whether you have a brand-new domain, a previously blacklisted IP, or simply want to maintain healthy sender scores during high-volume campaigns, Warmy handles the invisible technical work that determines whether your outreach succeeds or fails.
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Key Features Explained
AI Engine "Adeline"
Warmy's core technology is an adaptive learning AI called Adeline. Rather than following static warm-up rules, Adeline analyzes hundreds of parameters per mailbox—domain age, sending history, current reputation, mailbox provider responses, and real-time engagement signals.
Based on this analysis, the AI makes over 20 million micro-decisions daily across its user base: when to send warm-up emails, how many, to which recipients, with what content, and at what pacing. The algorithm constantly recalibrates based on live feedback, optimizing warm-up specifically for each mailbox's situation.
This adaptive approach outperforms fixed schedules because every domain's reputation context is different. What works for a 5-year-old domain won't work for one registered yesterday.
Hands-Off Warm-Up Automation
Once you connect a mailbox via SMTP/IMAP credentials, Warmy handles everything automatically. The platform schedules gradual sending that mirrors natural human behavior: emails sent at realistic intervals, opened after varying delays, scrolled through, sometimes replied to, and occasionally forwarded.
You can "set and forget" with default settings or customize daily volume caps, sending windows (time zones and hours), and pacing curves. For agencies managing multiple client mailboxes, all accounts appear in one dashboard with individual controls.
The warm-up continues running in the background while you send actual campaigns through your outreach platform of choice. Warmy doesn't replace your cold email tool—it runs alongside it, maintaining deliverability health.
Deliverability and Placement Testing
Before launching campaigns, you need to know where your emails actually land. Warmy's placement testing fires test emails to a seed list spanning major providers: Gmail, Outlook, Yahoo, and niche business email providers.
For each test, you see exactly whether the message landed in Primary Inbox, Promotions tab, or Spam folder—broken down by provider. If some providers show spam placement while others show inbox, you can troubleshoot specifically.
The testing also flags technical issues: SPF record problems, DKIM signature failures, DMARC policy issues, and DNSBL blacklist appearances. Fixing these technical foundations is often required before warm-up can repair reputation.
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Real-Mailbox Engagement Network
Effective warm-up requires realistic engagement from real mailboxes—not automated bots or dummy accounts that email providers can detect. Warmy's network includes thousands of active, authentic email addresses that participate in warm-up interactions.
When Warmy sends a warm-up email from your domain, it goes to a real inbox where it gets opened, scrolled through, sometimes clicked, and occasionally replied to. Spam-trapped emails get rescued—moved from spam to inbox and marked as "not spam" or "important."
These organic signals train ISPs to trust your domain. Gmail, Outlook, and other providers see that real humans engage positively with your emails, building the sender reputation that keeps your actual campaigns out of spam.
Multilingual and Custom Templates
Warming up a Spanish-language domain? German? French? Warmy supports 30+ languages for warm-up email content, ensuring the messages that build your reputation match your actual sending language and audience.
You can use Warmy's template library organized by topic (business, general, industry-specific) or upload your own templates. Custom templates are useful for warming with content that closely resembles your actual email style.
Agency-Ready Dashboard and Reporting
Color-coded charts show daily health scores, open rates, spam recovery statistics, and inbox placement trends over time. Watch reputation improve week by week as warm-up progresses.
Team features support inviting colleagues with role-based permissions. White-label PDF reports can be generated for clients without revealing Warmy branding. Multiple sending domains and mailboxes are monitored side-by-side.
For general email organization and management, see SaneBox.
Real-World Use Cases
New Domain Launch
Starting cold outreach from a fresh domain is risky—ISPs have no history to trust. Warmy warms new domains for 2-4 weeks before campaign launch, establishing the positive sender signals that prevent immediate spam placement.
Reputation Repair
Domains that have been blacklisted or spam-flagged need rehabilitation. Warmy's consistent positive engagement gradually rebuilds trust, moving mailboxes from spam placement back to primary inbox over time.
High-Volume Campaign Support
Sales teams running high-volume cold email campaigns use Warmy continuously to maintain deliverability under load. The warm-up activity provides baseline positive signals that offset the natural reputation strain of mass outreach.
Agency Client Onboarding
Lead generation agencies warm up client domains before launching campaigns, ensuring deliverability from day one. The agency dashboard manages multiple client accounts efficiently.
For LinkedIn outreach alongside warmed email campaigns, see Waalaxy or Sales Farmer.
Pricing (2026)
See official pricing for current rates. All plans are priced monthly per mailbox.
Starter — $49/month. 100 warm-up emails/day, 1 health test/month, 1 placement test/month. Basic warm-up for single mailboxes.
Business — $129/month. 300 warm-ups/day, 3 tests/month, custom pacing controls, language selection.
Premium — $189/month. 1,000 warm-ups/day, 10 tests/month, Google Postmaster integration, custom template uploads.
Expert — $279/month. 2,000 warm-ups/day, 50 tests/month, agency dashboard, priority support.
Platinum — $429/month. 5,000 warm-ups/day, 100 tests/month, full feature set for high-volume senders.
7-day free trial available on all plans, no credit card required.
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Pros and Cons
What We Like
AI-powered adaptive warm-up that optimizes for each mailbox
Real human mailbox engagement network (not bots)
Placement testing across Gmail, Outlook, Yahoo, and others
Technical diagnostics for SPF, DKIM, DMARC, and blacklists
30+ language support for international campaigns
7-day free trial without credit card
Agency dashboard for managing multiple clients
Continuous monitoring with health score tracking
What Could Be Better
Can get expensive for multiple mailboxes (per-mailbox pricing)
Full warm-up takes 1-4 weeks—not instant results
Requires ongoing subscription for maintained results
Dashboard has learning curve for new users
Higher tiers needed for reasonable test quantities
Warmy vs. Alternatives
vs. Mailwarm: Mailwarm is simpler and cheaper for basic warm-up. Warmy offers more advanced AI optimization and comprehensive placement testing capabilities.
vs. Lemwarm: Lemwarm is integrated with Lemlist's cold email platform. Warmy works with any email platform and offers deeper diagnostics and testing.
vs. Instantly: Instantly includes warm-up as part of its cold email tool. Warmy is dedicated warm-up with more sophisticated AI and diagnostic features for those using other outreach platforms.
vs. Manual warm-up: Manually building email history is free but inconsistent and time-consuming. Warmy automates with AI precision at scale.
vs. SmartReach AI: SmartReach includes built-in warm-up as part of its sales engagement platform. Warmy is dedicated warm-up with deeper functionality for those using other tools.
For comprehensive sales outreach including email, LinkedIn, and phone, see AiSDR.
Tips for Best Results
Start before you need it: Begin warm-up 2-4 weeks before campaign launch, not the day before.
Fix technical issues first: If placement testing reveals SPF/DKIM/DMARC problems, resolve those before expecting warm-up to help.
Don't rush volume: Gradual warm-up is more effective than aggressive pacing that triggers spam filters.
Continue during campaigns: Keep Warmy running while sending actual campaigns to maintain positive signals.
Monitor health scores: Watch for drops that indicate deliverability issues needing attention.
FAQ
What exactly is "email warm-up"?
Warm-up sends low-volume, high-engagement emails from a new or dormant mailbox to build positive sender reputation with ISPs. Without it, mass cold emails are likely to hit spam because providers have no history of trusting your domain.
How long does the warm-up process take?
Most users see healthy inbox placement within 1-4 weeks, depending on domain age, previous reputation history, and volume goals. New domains take longer than established ones with minor reputation issues.
Which email providers are supported?
Gmail, Outlook, Yahoo, Zoho, Amazon SES, SMTP gateways, and virtually any IMAP/SMTP-compatible email service. If you can configure SMTP credentials, Warmy can warm it.
Can I cancel anytime?
Yes. Warmy bills month-to-month with no long-term commitment. Pause or cancel from the billing dashboard. Note that stopping warm-up can lead to reputation decay over time.
Is my data secure?
Mailbox credentials are stored with bank-grade encryption. Warmy never accesses your actual email content beyond the synthetic warm-up threads it generates.
Does Warmy replace my cold email platform?
No. Warmy runs in parallel with your outreach tool of choice (Lemlist, SmartReach, Instantly, Apollo, etc.). It handles warm-up and deliverability; you still send campaigns through your preferred platform.
What happens if I stop using Warmy?
Sender reputation isn't permanent. Without ongoing positive signals, deliverability may gradually decline, especially for high-volume senders. Many users maintain warm-up continuously.
Final Verdict
If cold email is part of your growth strategy, email deliverability isn't optional—it's foundational. Warmy addresses the technical challenge that determines whether your outreach succeeds or fails.
The AI-powered approach, real-mailbox engagement network, and comprehensive placement testing provide visibility and optimization that most alternatives lack. For serious cold email senders, the investment typically pays for itself through improved reply rates and reduced list burn.
The 7-day free trial makes evaluation risk-free. If your domain needs deliverability help—or you're launching a new sending domain—Warmy deserves a test before your campaigns go out.
