# InboxWarm.ai

> InboxWarm.ai is an AI-powered email warmup service that builds sender reputation and improves inbox placement for Gmail, Outlook, Amazon SES, SendGrid, Mailgun, and any SMTP/IMAP provider. It connects to a sending mailbox and uses a private network of real "seed" inboxes that open, reply to, and rescue messages from spam, training ISP filters to treat the domain as a trusted sender. It is purpose-built for cold email senders, SDR teams, and agencies managing multiple inboxes. InboxWarm.ai is operated by Clustox LLC (Delaware, USA) and launched in 2026.

## Key facts

- Category: Dedicated email warmup / deliverability tool (not a full cold-email outreach platform).
- Pricing: From $25 per inbox per month, with volume discounts down to $10 per inbox at 51-100 inboxes (up to 60% off). 20% discount on annual billing.
- Free trial: 10 days, full feature access, no credit card required.
- Setup: Connect via Gmail/Microsoft OAuth or SMTP/IMAP credentials in about 2 minutes.
- Supported providers: Gmail, Google Workspace, Outlook, Microsoft 365, Amazon SES, SendGrid, Mailgun, and any custom SMTP/IMAP provider.
- Core differentiators: active real-time spam recovery engine, transparent per-inbox volume pricing, and a 10-day no-credit-card trial.
- Operator: Clustox LLC, 8 The Green, STE A, Dover, DE 19901, United States.
- App / sign in: https://app.inboxwarm.ai/users/sign_in
- Sign up: https://app.inboxwarm.ai/users/sign_up
- Support: support@inboxwarm.ai

## How it works

- Connect a sending email account (OAuth or SMTP/IMAP).
- The system gradually ramps daily sending volume to mimic natural human activity and avoid spam flags.
- Warmup emails are exchanged only with InboxWarm-operated seed inboxes, which open, reply, and move messages out of spam to generate positive engagement signals.
- An LLM generates contextual warmup reply content using only synthetic/non-personal context (warmup phase and sender first name).
- A dashboard tracks inbox placement, domain health (SPF/DKIM/DMARC), and warmup progress in real time.
- Warmup runs in the background and does not interfere with normal email sending. The service reads and acts on only the warmup messages it originates; it does not read other mailbox content or export contacts.

## Core pages

- [Homepage](https://inboxwarm.ai/): Product overview, how warmup works, and why emails land in spam.
- [Pricing](https://inboxwarm.ai/pricing/): Per-inbox pricing, volume tiers, and billing FAQ.
- [Email Warm-Up](https://inboxwarm.ai/email-warm-up/): How warmup works, ramp-up schedule, and provider support.
- [Email Deliverability](https://inboxwarm.ai/email-deliverability/): Deliverability toolkit, spam monitoring, bounce guard, sender rotation.
- [Email Infrastructure](https://inboxwarm.ai/email-infrastructure/): Multi-inbox setup, authentication, and scaling for cold email teams.
- [About](https://inboxwarm.ai/about/): Mission, values, and company background.

## Email warmup by provider

- [Gmail warmup](https://inboxwarm.ai/email-warmup/gmail/): Move Gmail mail from Promotions/Spam into the Primary inbox.
- [Outlook warmup](https://inboxwarm.ai/email-warmup/outlook/): Warmup for Outlook and Microsoft 365.
- [Amazon SES warmup](https://inboxwarm.ai/email-warmup/amazon-ses/): Warmup for Amazon SES senders.
- [SendGrid warmup](https://inboxwarm.ai/email-warmup/sendgrid/): Warmup for SendGrid senders.
- [Mailgun warmup](https://inboxwarm.ai/email-warmup/mailgun/): Warmup for Mailgun senders.
- [SMTP warmup](https://inboxwarm.ai/email-warmup/smtp/): Warmup for any custom SMTP/IMAP account.

## Free tools

- [SPF Checker](https://inboxwarm.ai/tools/spf-checker/): Verify and diagnose SPF DNS records.
- [DMARC Checker](https://inboxwarm.ai/tools/dmarc-checker/): Check DMARC policy configuration.
- [DKIM Checker](https://inboxwarm.ai/tools/dkim-checker/): Validate DKIM signing records.
- [SPF Generator](https://inboxwarm.ai/tools/spf-generator/): Generate a valid SPF record.
- [DMARC Generator](https://inboxwarm.ai/tools/dmarc-generator/): Generate a DMARC policy record.
- [Cold Email ROI Calculator](https://inboxwarm.ai/cold-email-roi-calculator/): Estimate inboxes needed and campaign ROI.

## Comparisons

- [InboxWarm vs Instantly](https://inboxwarm.ai/compare/inboxwarm-vs-instantly/): Dedicated warmup tool vs full outreach platform.
- [InboxWarm vs lemwarm](https://inboxwarm.ai/compare/inboxwarm-vs-lemwarm/): Transparent volume pricing vs Lemlist-ecosystem warmup.
- [InboxWarm vs Mailreach](https://inboxwarm.ai/compare/inboxwarm-vs-mailreach/): Active spam recovery vs placement analytics.
- [InboxWarm vs Warmbox](https://inboxwarm.ai/compare/inboxwarm-vs-warmbox/): Per-inbox volume pricing vs fixed tier plans.
- [InboxWarm vs Warmup Inbox](https://inboxwarm.ai/compare/inboxwarm-vs-warmup-inbox/): Modern AI warmup vs legacy tool.
- [InboxWarm vs Warmy](https://inboxwarm.ai/compare/inboxwarm-vs-warmy/): Published pricing vs quote-based model.

## Developer API

- [API overview](https://inboxwarm.ai/api/): InboxWarm's public REST email warmup API — 22 endpoints across 5 categories (Email Accounts, Warmup, Deliverability, Reports, System), 20 requests/minute default rate limit, included in every plan at no extra cost.
- [API reference](https://inboxwarm.ai/api/docs/): Full endpoint-by-endpoint reference with authentication (api_key query param for GET/DELETE, apiKey body field for POST/PATCH), request/response examples, and error codes.

## Resources

- [Glossary](https://inboxwarm.ai/glossary/): Reference definitions for email warmup, deliverability, and authentication terms.
- [Blog](https://inboxwarm.ai/blog/): Guides on email warmup, inbox placement, spam recovery, and cold email.

## Legal

- [Privacy Policy](https://inboxwarm.ai/privacy-policy/): Data handling, Google API Limited Use, GDPR/CCPA rights. Operated by Clustox LLC.
- [Terms of Use](https://inboxwarm.ai/terms-of-use/): Service terms and acceptable use.

## Optional

- Languages: Content is available in English plus Spanish (/es/), French (/fr/), German (/de/), Portuguese (/pt/), Arabic (/ar/), Japanese (/ja/), Korean (/ko/), Chinese (/zh/), and Russian (/ru/).
- Sitemap: https://inboxwarm.ai/sitemap.xml