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Side-by-side comparisonBy the Warmy deliverability team Updated
No credit card required
Warmy brings Adeline AI, personalized warm-up, real link clicks, inbox placement testing, verification and reputation monitoring together in one all-in-one deliverability platform.
A send-to-test-address diagnostic that scores message and sending-server quality, with JSON reporting for application integration.
Key takeaways
Good to knowWarmy goes beyond a single email tool: Adeline AI, warm-up, testing, monitoring and verification work together to improve your deliverability.
Warmy brings ongoing optimization, actionable intelligence and deliverability measurement into one platform. See how that broader coverage compares with the specialist capabilities below.
| Feature | Warmy | Mail-Tester |
|---|---|---|
| Primary focus | All-in-one, self-serve email deliverability infrastructure | A send-to-test-address diagnostic that scores message and sending-server quality, with JSON reporting for application integration. |
| Best-fit audience | Teams improving and measuring sender reputation across their existing sending stack. | Senders and developers needing a quick message-level diagnostic rather than an enterprise placement program. |
| Generated address | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Web interface generates a random test email address. |
| Real-message submission | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Send from your newsletter or email software. |
| Score retrieval | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Check the score after the test message is received. |
| Message diagnostics | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Analyzes the submitted message. |
| Server diagnostics | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Analyzes the mail server. |
| Sending-IP diagnostics | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Analyzes the sending IP. |
| Detailed configuration report | Adeline AI co-pilot and AI template optimizer | Reports what is configured properly and what is not. |
| Free report retention | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Free reports remain accessible for seven days. |
| Account-prefix retention | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Account-prefix reports remain accessible for thirty days. |
| Overwrite behavior | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Another message to the same address replaces the previous test. |
| JSON output | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Append format=json to retrieve structured test results. |
| Unique test identifiers | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | Choose unique address suffixes to avoid overwriting tests. |
| Selective tests | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | The test query parameter requests a selected main diagnostic. |
| Localized output | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | The lang parameter selects a report language. |
| Debug view | Warmy focuses on reputation, placement testing and monitoring; this specialist capability is not presented as an equivalent Warmy feature. | format=dbug exposes a structured inspectable result. |
| Pricing and billing | From $49/month, billed monthly | Official checkout displays $ subscriptions and one-time packs; currency code and taxes unverified. Monthly subscriptions or one-time test packs |
| Trial and free access | Seven days, no credit card required | Free web interface documented; exact current free-test rate limits unverified. |
The detailed analysis
Senders and developers needing a quick message-level diagnostic rather than an enterprise placement program.
Mail-Tester analyzes a submitted message, sending server and IP, and returns a detailed quality report. The workflow starts by sending a real message to its generated address.
The FAQ explicitly warns that different spam filters and individual preferences produce different outcomes. A strong score is useful evidence of basic configuration quality, not a guarantee that Gmail, a corporate gateway or every subscriber will accept the same message into the inbox.
The official workflow asks users to send from their newsletter or email software to the provided address, then retrieve the score after receipt. This checks the message that actually traversed that route.
Use the same production sender identity and delivery path when investigating a campaign. Treat a test from another sending tool as a different configuration experiment; the service’s report describes the received sample, not every route your organization operates.
The API returns report information as JSON using a chosen account prefix and address suffix. Query parameters can select a particular test and a report language.
That makes it suitable for embedding diagnostics into an internal deployment checklist. Use unique identifiers per run and preserve the returned result in your own audit system when longer-lived evidence is required; the documented address overwrite behavior otherwise destroys the previous sample.
Free reports remain available for seven days, while registered account-prefix results remain for thirty days. Sending again to the same test address replaces the prior report immediately.
This is a material workflow constraint for reproducible QA. Assign one test address to each candidate message or build, and avoid using a shared static address if reviewers must compare several campaign revisions later.
The official checkout lists monthly test subscriptions and one-time test packs. It displays dollar amounts but does not establish a currency code or complete tax treatment in the reviewed extract.
Choose between recurring and occasional testing based on workload, and confirm checkout terms before purchase. Do not describe a pack price as a monthly subscription or assume that a diagnostic allowance includes sending infrastructure.
Warmy describes automated email warm-up with conversations, replies and gradually increasing activity. These actions are intended to develop and maintain sender reputation.
Mail-Tester’s official workflow instead analyzes a message deliberately sent to a test address. It is a practical diagnostic checkpoint alongside a warm-up program, not evidence that a score alone performs reputation-building engagement.
The Warmy advantage
From Adeline’s next-step guidance to real engagement and provider-level measurement, Warmy connects the work that separate email tools leave to your team.
Adeline connects authentication, DNS, inbox placement, blocklists, content, engagement and provider signals into one picture. She builds personalized deliverability plans, detects spam risk and explains what to change next.
Personalized timing, volume and pacing, with gradual ramp-up and engagement that includes opens, replies, important markings and moving messages out of spam.
Warmy’s engagement includes real clicks on your links, alongside opens and other natural mailbox interactions.
1M+ real, protected Google Workspace, Microsoft 365, and B2C mailboxes
500,000+ real US seed accounts, desktop and mobile; rotated monthly; speeds up warmup
Included: 5–50 tests/month by tier, with automated testing. Provider-level results distinguish inbox, Promotions and spam, so you can measure progress instead of relying on SMTP acceptance alone.
Domain/IP reputation tracking, blacklist alerts, spam-placement reports
SPF, DKIM, and DMARC tracking, record checks, and DMARC report analysis
Direct Google Postmaster integration
Check address validity as part of the wider deliverability workflow, alongside reputation work, placement testing and monitoring.
AI template optimization, custom warm-up topics and templates, and conversations in 30+ languages.
Multiple mailboxes and domains; 100 to 5,000 warmup emails/day by plan. Auto-archive keeps warm-up conversations out of your working inbox.
Klaviyo, Mailchimp, HubSpot, SendGrid, ActiveCampaign, Google Workspace, Microsoft 365, and SMTP. Self-serve setup in minutes via OAuth or SMTP/IMAP.
Documented API included on every plan. 24/7 human support; dedicated CSM and deliverability consultant on Expert/Platinum.
Allowances and dedicated support vary by plan. Plans starting from $49 / month.
Plans and total cost
| Pricing detail | Warmy | Mail-Tester |
|---|---|---|
| Starting price | $49/ month | Official checkout displays $ subscriptions and one-time packs; currency code and taxes unverified. |
| Billing | Monthly | Monthly subscriptions or one-time test packs |
| Free trial | Seven days, no credit card required | Free web interface documented; exact current free-test rate limits unverified. |
| Also included | Adeline AI, warm-up, placement tests, monitoring, verification and API access; allowances vary by plan. | See the individual features and published plan allowances below. |
Plans starting from $49 / month. See Warmy’s five plans
A mailbox subscription, an address-verification credit, a rendering test and an SMTP sending allowance buy different outcomes. Compare total cost using your own mailbox count, list size, testing frequency and sending volume; do not equate a lower unit price with equivalent coverage.
Social proof
Rated 4.9/5 on G2 and trusted by 35,000+ businesses.
“Warmy has been a game changer for us. The platform pays for itself many times over.”
“If you do cold email, Warmy will increase your efficiency, improve your deliverability, and cut your costs.”
Thomas Tzouridis“I've purchased many marketing tools before. Often, once you buy, you're on your own. With Warmy, they care about you.”
The verdict
| If you want… | Choose |
|---|---|
| Everything in one platformWarm-up, placement tests, verification, authentication and reputation monitoring in one connected workflow. | Warmy |
| Adeline AI expertisePersonalized plans, predictive spam-risk detection and clear next steps from your AI deliverability expert. | Warmy |
| Real engagement and seed accountsA 1M+ mailbox network, real link clicks and 500,000+ US seed accounts. | Warmy |
| Expert help and an easy startSelf-serve setup, API access and 24/7 human support; dedicated consultant options on higher tiers. | Warmy |
| Check a newsletter through its intended sending software. | Mail-Tester |
| Store JSON diagnostics in a deployment checklist. | Mail-Tester |
| Allocate unique test addresses to campaign revisions. | Mail-Tester |
A practical evaluation
Check a newsletter through its intended sending software. Keep that objective separate from your sender-reputation and placement baseline.
Test a representative message with a consistent provider mix. Record authentication, inbox and spam placement before changing the sending workflow.
The FAQ explicitly warns that different spam filters and individual preferences produce different outcomes. A strong score is useful evidence of basic configuration quality, not a guarantee that Gmail, a corporate gateway or every subscriber will accept the same message into the inbox.
Perfect scores cannot guarantee inbox placement. Keep specialist tooling where it serves a separate job. Coordinate any overlapping warm-up schedules instead of doubling engagement volume.
Compare provider-level placement alongside specialist results, bounces and complaints. Address validity, rendering previews and SMTP acceptance alone do not prove inbox placement.
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