EmailEngine
EmailEngine is a self-hosted email API by Postal Systems OÜ in Tallinn, Estonia.
What EmailEngine is
EmailEngine is a self-hosted email API by Postal Systems OÜ in Tallinn, Estonia. It connects Gmail, Google Workspace, Microsoft 365, Outlook.com and IMAP mailboxes through one REST API. Mailbox message and state changes can trigger webhooks, and outgoing mail can use the connected account’s SMTP server or provider API. Authentication includes managed OAuth2, Google Workspace service accounts, Microsoft 365 app-only access and shared or delegated mailboxes. An optional beta MCP server lets approved AI clients search, read, file, draft and send messages. The administration interface shows sync status and queue details, with Prometheus and Grafana monitoring support. Data remains on the customer’s infrastructure; message bodies are fetched on demand, while sync metadata uses Redis. AES-256-GCM encryption is available when EENGINE_SECRET is configured. A server and Redis using noeviction are required. Annual subscription pricing is $1,450/yr, excluding VAT where applicable, with a 14-day full trial.
Good
- Unified REST API for major mailbox providers
- Webhooks report mailbox changes
- Managed OAuth2 and delegated mailbox support
- Customer-controlled infrastructure and Redis
- 14-day full-functionality trial
Watch out
- No free plan
- Requires a server and Redis
- Does not support POP3 or ActiveSync
- No SOC 2 or ISO 27001 certification
Who it suits
It suits CRM, SaaS and AI businesses, teams handling many mailboxes, and organisations with data-residency requirements. Self-hosting requires operational infrastructure.
Verdict
EmailEngine centralizes mailbox connectivity, events and sending behind a self-hosted API. Its infrastructure requirements and annual cost suit teams prepared to operate their own deployment.
Plans and prices
From EmailEngine's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Annual subscription | $1,450 a year | Unlimited connected mailboxes · unlimited production, staging and development instances · unlimited API calls and webhooks · support directly from the developer · Renews annually; prices exclude VAT where applicable. |
| Enterprise perpetual licence | Priced on request | Perpetual licence · offline verification · invoice or wire transfer · custom contract and licence terms · same features and support · Paid once; contact for terms and pricing. |
The facts
Each one read from EmailEngine's own pages, with the date it was checked.
What it does
- AI agents
- An optional MCP server, currently in beta, lets connected AI clients search, read, file, draft and send email with approved access.checked 8 Oct 2026
- Authentication
- It offers managed OAuth2, Google Workspace service accounts, Microsoft 365 app-only access, and shared or delegated mailbox support.checked 8 Oct 2026
- Compliance
- EmailEngine does not come with SOC 2 or ISO 27001 certification; its compliance posture depends on the environment where it is deployed.checked 8 Oct 2026
- Data handling
- EmailEngine runs on the customer’s infrastructure, caches sync metadata in the customer’s Redis, and fetches message bodies on demand rather than storing them.checked 8 Oct 2026
- Deployment requirement
- Running EmailEngine requires a server and Redis, which must use the noeviction policy.checked 8 Oct 2026
- Email handling
- It sends webhooks when mailbox messages or state change and can send email through the connected account’s SMTP server or provider API.checked 8 Oct 2026
- Intended users
- The maker describes CRM, SaaS and AI businesses, and teams with data-residency requirements or many mailboxes, as fitting use cases.checked 8 Oct 2026
- Notable limits
- It does not support POP3, ActiveSync or Exchange Web Services, and it does not keep a sent-mail archive or webhook delivery history.checked 8 Oct 2026
- Operations
- The admin interface includes account sync status and queue inspection, and the product provides a Prometheus endpoint and Grafana dashboard.checked 8 Oct 2026
- Product
- EmailEngine is a self-hosted email API that connects existing Gmail, Microsoft 365 and IMAP mailboxes through a unified REST API.checked 8 Oct 2026
- Provider integrations
- It supports Gmail and Google Workspace, Microsoft 365 and Outlook.com, plus IMAP servers; native integrations use Gmail API and Microsoft Graph.checked 8 Oct 2026
- Security
- Stored mailbox credentials and OAuth2 tokens can be encrypted with AES-256-GCM when the deployment’s EENGINE_SECRET key is configured.checked 8 Oct 2026
- Support
- The maker says support goes directly to the developer who wrote the code, and its annual subscription includes developer support.checked 8 Oct 2026
The company
- Headquarters
- Tallinn, Estoniachecked 28 Sep 2026
- Maker
- EmailEngine is made by Postal Systems OÜ, an Estonian company based in Tallinn; its about page identifies Andris Reinman as the founder and developer.checked 8 Oct 2026
Money
- Trial
- Each installation can start a full-functionality 14-day trial from its dashboard without signup or a credit card.checked 8 Oct 2026
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