Posta is a private, secure mail system exclusively for @subhr.in addresses. It uses a custom C backend server, Clerk authentication with RS256 JWT verification via OpenSSL, and PostgreSQL database isolation for maximum privacy and security.

Posta is exclusively for @subhr.in domain users. Only addresses ending in @subhr.in can send and receive mail within this closed network.

How does Posta ensure privacy?

Posta uses zero-trust architecture: the Next.js frontend has zero database credentials or access. All mail traffic routes through a custom C server that validates Clerk JWT sessions using OpenSSL RS256 verification. Database is completely isolated from the web.

What authentication does Posta use?

Posta uses Clerk authentication with RS256 JWT signatures verified by the C backend via OpenSSL. No shared secrets, no token forwarding - cryptographic verification at the edge.

How does email delivery work?

Incoming SMTP traffic flows on port 2525. A background database-driven worker manages queue status, retry logic, and delivery confirmation for both SMTP and web submissions. SMTP and web share one async queue pipeline.

Posta is a private, secure mail system exclusively for @subhr.in addresses. It uses a custom C backend server, Clerk authentication with RS256 JWT verification via OpenSSL, and PostgreSQL database isolation for maximum privacy and security.

Posta is exclusively for @subhr.in domain users. Only addresses ending in @subhr.in can send and receive mail within this closed network.

How does Posta ensure privacy?

Posta uses zero-trust architecture: the Next.js frontend has zero database credentials or access. All mail traffic routes through a custom C server that validates Clerk JWT sessions using OpenSSL RS256 verification. Database is completely isolated from the web.

What authentication does Posta use?

Posta uses Clerk authentication with RS256 JWT signatures verified by the C backend via OpenSSL. No shared secrets, no token forwarding - cryptographic verification at the edge.

How does email delivery work?

Incoming SMTP traffic flows on port 2525. A background database-driven worker manages queue status, retry logic, and delivery confirmation for both SMTP and web submissions. SMTP and web share one async queue pipeline.

Yes, Posta is free to use for @subhr.in domain users. There are no subscription fees or hidden costs.

Can I use my own domain?

Currently Posta only supports @subhr.in addresses. The service is designed as a closed, private mail network for this specific domain.

Your private domain mail network for @subhr.in addresses.

Send and receive plain-text messages instantly between @subhr.in addresses. Powered by a custom, secure C backend server and Clerk authentication to keep your communications fast, lightweight, and completely private.

Frequently Asked Questions

What is Posta?: Posta is a private, secure mail system exclusively for @subhr.in addresses. It uses a custom C backend server, Clerk authentication with RS256 JWT verification via OpenSSL, and PostgreSQL database isolation for maximum privacy and security.
Who can use Posta?: Posta is exclusively for @subhr.in domain users. Only addresses ending in @subhr.in can send and receive mail within this closed network.
How does Posta ensure privacy?: Posta uses zero-trust architecture: the Next.js frontend has zero database credentials or access. All mail traffic routes through a custom C server that validates Clerk JWT sessions using OpenSSL RS256 verification. Database is completely isolated from the web.
What authentication does Posta use?: Posta uses Clerk authentication with RS256 JWT signatures verified by the C backend via OpenSSL. No shared secrets, no token forwarding - cryptographic verification at the edge.
How does email delivery work?: Incoming SMTP traffic flows on port 2525. A background database-driven worker manages queue status, retry logic, and delivery confirmation for both SMTP and web submissions. SMTP and web share one async queue pipeline.
Is Posta free?: Yes, Posta is free to use for @subhr.in domain users. There are no subscription fees or hidden costs.
Can I use my own domain?: Currently Posta only supports @subhr.in addresses. The service is designed as a closed, private mail network for this specific domain.

Ready for your private @subhr.in address?

Join the private mail network. Secure, fast, and completely yours.