Mailwarm
Mailwarm is a web-based email warmup and deliverability service intended to improve sender reputation and inbox placement.
What Mailwarm is
Mailwarm is a web-based email warmup and deliverability service intended to improve sender reputation and inbox placement. It automates scheduled warmup across Gmail, Outlook, Microsoft 365, Yahoo and SMTP, with gradual volume increases. Interactions can include opens, replies, moving messages from spam and marking them important. Mailwarm says its engagement network contains 50,000+ real email accounts across Gmail, Outlook, Yahoo and Microsoft 365.
The service monitors spam scores and inbox placement, with provider-level insights and early issue detection. Checks include SPF, DKIM and DMARC validation, blacklist detection, and SMTP and IMAP configuration checks. It lists one-click Gmail and Outlook or Office 365 connections, as well as custom SMTP support. Mailwarm says OAuth connections do not require password sharing and its pricing page says IMAP access is not required. It can detect invalid email addresses and deactivate invalid inboxes to reduce bounce risk. There is no free plan or traditional free trial, though a free email spam checker is offered.
Good
- Automates warmup across major email providers and SMTP
- Monitors spam scores and inbox placement
- Checks SPF, DKIM, DMARC and blacklists
- OAuth connections do not require password sharing, per Mailwarm
Watch out
- No free plan or traditional free trial
- Starter costs $69 a month, billed annually
- Starter supports one mailbox or SMTP connection
- Starter allows up to 50 warmup emails per day
Who it suits
Mailwarm identifies sales and outbound teams, founders launching domains, agencies managing inboxes and businesses recovering from spam placement as users it serves. It may suit teams seeking warmup and deliverability monitoring through a web service.
Verdict
Mailwarm combines scheduled warmup with inbox placement monitoring and configuration checks. The warmup service is paid, starting at $69 a month billed annually, and has no traditional free trial.
Plans and prices
From Mailwarm's own pricing page, checked 15 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Starter | $69 a month | Up to 50 warmup emails/day · Up to 50 replies/day · 200+ positive interactions · 1 mailbox/SMTP · 1 user · 1 expert call/month · Billed annually |
| Growth | $159 a month | Up to 200 warmup emails/day · Up to 200 replies/day · 800+ positive interactions · 3 mailboxes/SMTPs · 2 users · 4 expert calls/month · Billed annually |
| Scale | $479 a month | Up to 500 warmup emails/day · Up to 500 replies/day · 2000+ positive interactions · 10 mailboxes/SMTPs · 5 users · On-demand expert calls · Billed annually |
| Tailored Plan | Priced on request | Everything in Scale · Unlimited mailboxes, users, warmup emails and replies · Dedicated deliverability expert |
The facts
Each one read from Mailwarm's own pages, with the date it was checked.
What it does
- Account connection
- Mailwarm says its OAuth connections do not require password sharing; it also says no IMAP access is required on its pricing page.checked 8 Oct 2026
- Authentication checks
- Mailwarm checks SPF, DKIM, DMARC, SMTP and IMAP configuration and detects blacklist listings.checked 15 Oct 2026
- Automated warmup
- The service automates warmup across Gmail, Outlook, Microsoft 365, Yahoo, and SMTP, with progressive volume ramp-up and scheduling.checked 8 Oct 2026
- Bounce prevention
- Mailwarm advertises email verification, invalid-address detection and bounce prevention to protect domain reputation.checked 15 Oct 2026
- Connection method
- Gmail and Outlook connections use OAuth, while custom SMTP servers are supported; the pricing page says IMAP access is not required.checked 15 Oct 2026
- Content warmup
- Users can supply their own email templates so warmup resembles their real campaign content and sending patterns.checked 15 Oct 2026
- Developer and self-hosting availability
- Palisade reports that Mailwarm's published materials describe a commercial service but provide no open-source licence, public repository or self-hosted deployment.checked 15 Oct 2026
- Engagement actions
- Warmup interactions can include opens, replies, moving messages from spam, and marking messages as important.checked 8 Oct 2026
- Engagement network
- The feature page says Mailwarm uses more than 50,000 real inboxes across Gmail, Outlook, Yahoo and Microsoft 365 for opens, replies and conversations.checked 15 Oct 2026
- Funding and acquisition
- Crunchbase lists Mailwarm as seed-funded, acquired by mailX and headquartered in Paris, France, with a 1–10 employee range.checked 15 Oct 2026
- Gmail setup
- The Gmail guide instructs users to create a campaign, sign in with Google and grant permission for Mailwarm to send messages.checked 15 Oct 2026
- Help documentation
- The help center includes onboarding, troubleshooting, Gmail or Google Workspace, Mailgun SMTP, generic SMTP and launch-guide articles.checked 15 Oct 2026
- Human-like actions
- Its engagement automation includes replies, archive actions, important marking, variable delays and conversation threads.checked 15 Oct 2026
- Infrastructure
- The terms identify Amazon Web Services as Mailwarm's technical infrastructure provider.checked 15 Oct 2026
- Infrastructure checks
- Mailwarm lists SPF, DKIM, and DMARC validation, blacklist detection, and SMTP and IMAP configuration checks.checked 8 Oct 2026
- Integrations
- Official pages list Gmail, Outlook or Office 365, Yahoo, Zoho, SendGrid, Mailgun and other SMTP services.checked 15 Oct 2026
- Licence
- The terms grant only a limited proprietary use licence and prohibit copying, modification, reverse engineering and mirroring.checked 15 Oct 2026
- Limit: Capterra integrations and UI
- Older Capterra reviews report that only SMTP or Gmail worked at the time, wanted faster integration delivery and roadmap updates, and found the UI/UX improvable.checked 15 Oct 2026
- Limit: G2 reporting and control
- G2 reviewers repeatedly ask for deeper analytics, more mailbox-performance detail, more customization and provider-specific controls; one calls the service expensive and another says warmup can feel slow.checked 15 Oct 2026
The company
- Company founding
- Y Combinator lists Mailwarm as founded in 2020 and part of its Summer 2020 batch.checked 15 Oct 2026
- Company location
- Y Combinator lists the company location as Dubai, United Arab Emirates.checked 15 Oct 2026
- Company team size
- Y Combinator lists a team size of 10.checked 15 Oct 2026
- Legal company
- The service agreement identifies the provider as COMUSE SAS, registered at 57 avenue de Bretagne, Rouen, France, registration 849350780.checked 15 Oct 2026
Money
- Free tools
- The site offers a free email spam checker, while describing the email warmup service as having no traditional free trial.checked 8 Oct 2026
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