What Mailwarm does

Mailwarm is a SaaS email warmup and deliverability platform operated by COMUSE SAS, founded in 2021 and headquartered in Rouen, France, with distributed operations in Paris, Casablanca, and Dubai. The product automates positive email interactions (sending, opening, replying, marking as important, and rescuing from spam) across a network of 50,000+ aged, maintained inboxes to build sender reputation and improve inbox placement for Gmail, Outlook/Microsoft 365, Yahoo, Zoho, and SMTP-based providers including SendGrid, AWS SES, and Mailgun. Live inbox-vs-spam placement tracking runs 24/7 at the provider level, and every paid plan includes expert deliverability sessions. The go-to-market is hybrid: a self-serve PLG funnel on app.mailwarm.com with a 2-minute setup, layered with affiliate distribution (50% first-purchase, 25% recurring via FirstPromoter), Calendly-driven expert consultations, and use-case pages targeting agencies, founders, sales teams, marketers, newsletter creators, cold outbound operators, and developers.

The company monetizes through three subscription tiers (Starter, Growth, Scale) on monthly or annual billing, complemented by a freemium suite of standalone email tools (Spam Checker, Blacklist Checker, SPF/DKIM/DMARC Checkers, Email Checker, Gmail Generator, Email Signature Generator) that serve as top-of-funnel SEO assets. Mailwarm 2.0, launched in February 2026, added multi-account management, advanced deliverability and reputation monitoring, multi-provider warmup, and provider-level spam score tracking. The platform is hosted on AWS in Ireland and is GDPR-compliant. Mailwarm reports a base of 10,000+ teams including Michelin, Microsoft Copilot, Deel, Princeton, BetterHelp, and Berkeley, and has been recognized with a #1 Product Hunt ranking and selection by Y Combinator and Station F.

Mailwarm is a small team (1-10 employees) backed by Y Combinator ($125K seed, August 2020) and Kima Ventures, led by co-founders Gonzague Hacher and Amine Benjelloun (CTO). The company is privately held with no disclosed revenue, valuation, or subsequent funding rounds beyond the initial YC seed and follow-on YC-affiliated and Kima participation.

Name

Mailwarm

Legal name

COMUSE SAS

Website

https://mailwarm.com

Company type

Private

Founded year

2021

Operating status

Operating

Headcount range

1–10 employees

Short description

Mailwarm is a SaaS email warmup and deliverability platform that automates engagement across 50,000+ aged inboxes to raise sender reputation and inbox placement for cold outbound, sales, agency, and founder users.

Ownership category

akta.pro rank

Product category

Email Deliverability Software

NAICS

Computing Infrastructure Providers, Data Processing, Web Hosting, and Related Services (5182)

SIC

Services-Prepackaged Software (7372)

akta.pro primary industry

Email Authentication & Domain Protection (DMARC/SPF/DKIM) (HDADAKAC)

akta.pro secondary industries

Email Marketing Services (Campaign Strategy, Design, Deliverability) (MPAAAIAA), Email Marketing Services (Campaigns, Deliverability, Lifecycle) (BPAFAKAB)

Keywords

• Email warmup service
• Email deliverability platform
• Sender reputation management
• Inbox placement tracking
• Cold email infrastructure

Headquarters

HQ city

Paris

HQ country

France

HQ region

Europe

Offices4 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Infrastructure, Marketing or Sales, Personnel, Operations

Revenue model

1. Subscription Plans (Starter, Growth, Scale): Mailwarm operates on a recurring subscription model with three named tiers (Starter, Growth, Scale). Plans are available on monthly or annual billing cycles. Annual plans require full upfront payment and are non-refundable once paid. Subscriptions auto-renew at the end of each term. The number of Interactions (automated email exchanges) generated may be subject to plan-specific fees. The company also promotes a 30% discount coupon (PH30OFF) for first-time sign-ups.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels7 records

Core offering

Mailwarm provides an automated email warmup SaaS platform that sends and receives interactions across a network of 50,000+ aged, maintained inboxes to build sender reputation and improve inbox placement. The service supports Gmail, Outlook/Microsoft 365, Yahoo, Zoho, and SMTP-based providers including SendGrid, AWS SES, and Mailgun, and includes live, 24/7 inbox vs. spam placement tracking plus expert deliverability sessions on every plan.

Product overview

Mailwarm is an email warmup and deliverability SaaS platform with a hybrid freemium model offering both paid subscription tiers (Starter, Growth, Scale) and free standalone tools. The core offering consists of email warmup services for Gmail, Outlook/Microsoft 365, Yahoo, and SMTP-based providers (SendGrid, AWS SES, Mailgun). The platform operates a network of 50,000+ real mailboxes to generate authentic engagement signals (opens, replies, spam rescues) that improve sender reputation and inbox placement. In February 2026, Mailwarm launched its Mailwarm 2.0 platform featuring multi-account management, advanced deliverability monitoring, and multi-provider warmup. Alongside the paid warmup services, Mailwarm offers a suite of 8+ free email tools including Email Signature Generator, Email Checker, Email Generator, Gmail Generator, DMARC Checker, DKIM Checker, SPF Checker, Blacklist Checker, and Spam Checker.

Differentiator

Problem solved

Functional benefit

Products and services

• Email Warmup Tool Primary email warmup service that improves sender reputation and email deliverability by generating automated positive interactions (opens, replies, spam rescues, importance marking) across Mailwarm's network of 50,000+ real inboxes, for businesses running outbound, marketing, or transactional email.
• SMTP Warmup Email warmup service for SMTP-based platforms including SendGrid, AWS SES, Mailgun, and other SMTP providers, allowing users to connect SMTP credentials for warmup; targets developers and teams running transactional or high-volume sending infrastructure.
• Gmail Warmup Specialized warmup service for Gmail accounts and Google Workspace domains, with provider-level control and Gmail-specific deliverability optimization; aimed at Google Workspace users and Gmail-based outbound teams.
• Microsoft/Outlook Warmup Specialized warmup service for Outlook and Microsoft 365 accounts, with Microsoft-specific deliverability features and inbox placement tracking for users sending through Microsoft-hosted mailboxes.
• Yahoo Warmup Specialized warmup service for Yahoo Mail accounts with Yahoo-specific deliverability optimization, for users whose recipients primarily use Yahoo Mail.
• IP Warmup Email warmup service focused on building IP reputation for domains and sending infrastructure, for teams sending from dedicated IPs that need to ramp up sending volume safely.
• Mailwarm 2.0 Next-generation version of Mailwarm's email warmup platform introducing multi-account management, advanced deliverability and reputation monitoring, multi-provider warmup, and provider-level spam score tracking across the 50,000+ mailbox network.
• Free Email Signature Generator Free online tool for creating professional email signatures with templates (Professional, Modern, Minimal), customizable accent colors, social media links, and real-time preview, offered as a standalone free utility to attract organic traffic.
• Free Email Checker Free email validation tool that verifies email address validity through syntax checking, domain DNS records, MX record validation, SMTP verification, and risk detection for disposable and catch-all addresses, with 5 free verifications available.
• Free Email Generator Free fake email address generator for testing and development purposes that generates realistic or random email addresses, supports custom domains, and creates batches up to 100 emails.
• Gmail Generator Free tool for creating Gmail aliases using the plus trick and dot variations, including auto filter setup for organizing emails by category.
• Free DMARC Checker Free tool for validating DMARC records by querying DNS at _dmarc.yourdomain.com, including policy detection, syntax validation, and policy recommendations.
• Free DKIM Checker Free tool for validating DKIM record configuration by querying DNS with specified selectors to verify cryptographic signature setup for email authentication.
• Free SPF Checker Free tool for verifying SPF records to confirm authorized mail servers for email sending.
• Free Blacklist Checker Free tool for checking if a domain or IP is blacklisted across major spam databases.
• Free Spam Checker Free tool for analyzing email content for spam triggers before sending campaigns.

Quantifiable outcome

• 31% increase in Microsoft inbox placement reported by Prime Match Recruiting
• +3 more outcomes

Named customers5 records

Segments7 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration8 records

AI capability2 records

Feature5 records

Partnerships

Two partnerships are on record, tiered minor.

• Station FminorStrategic or Co-development PartnerMailwarm was recognized by Station F, Europe's largest startup campus. This recognition provided visibility and access to the Station F ecosystem.
• Amazon Web Services (AWS)minorOthersMailwarm's technical infrastructure is provided by Amazon Web Services. Per the Terms of Use, AWS hosts the infrastructure that powers Mailwarm's service. User data is stored in AWS infrastructure in Ireland.

Scale indicators4 records

Recent moves2 records

Expansion highlights6 records

Direct peers

• Warmbox.ai: Dedicated email warmup SaaS that builds sender reputation through automated interactions. Closely comparable to Mailwarm in core product, target customer (cold outreach teams), and self-serve PLG motion.
• Mailreach: Email warmup and deliverability tool targeting B2B sales teams and agencies. Competes head-to-head with Mailwarm on inbox placement improvement, warmup automation, and SMB/agency pricing tiers.
• TrulyInbox: Email warmup platform offering automated reputation-building for Gmail, Outlook, and SMTP accounts. Directly comparable product offering and customer overlap with Mailwarm's cold outbound and sales segments.
• Lemwarm: Email warmup service operated by Lemlist, one of the most established players in the cold outreach space. Directly competes with Mailwarm on automated warmup to improve sender reputation and inbox placement.
• Warmy: Email deliverability and warmup platform with multi-provider support and reputation monitoring. Comparable to Mailwarm in warmup-as-a-service model and target audience of senders and agencies.

Emerging players

• ZeroBounce: Email validation and deliverability platform offering list cleaning, verification, and inbox placement testing. Adjacent to Mailwarm with overlapping free tools (email checker, blacklist checker) and shared audience.
• Hunter.io: Email finding, verification, and outreach platform with some deliverability tooling. Adjacent competitor overlapping with Mailwarm on email verification and sender reputation concerns.

Broad incumbents

• Smartlead.ai: Cold email automation platform that includes warmup and deliverability features. Competes with Mailwarm on the warmup layer but is a broader outreach suite targeting agencies and sales teams.
• Instantly.ai: Larger cold email outreach platform with built-in email warmup capabilities. Overlaps with Mailwarm on the warmup functionality but operates a much broader sales engagement stack with venture-scale funding.
• Lemlist: Established cold outreach platform that owns Lemwarm; combines email automation, personalization, and warmup. A broader incumbent whose warmup product is a direct competitor to Mailwarm.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks5 records

Key highlights6 records

Customer concentration

• Xx.com/mailwarm
• Facebookfacebook.com/Mailwarm-102161834695215
• LinkedInlinkedin.com/company/mailwarmhq

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles2 records

Funding overview

Funding rounds1 record

Investors1 record

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Mailwarm