An email API for developers bringing their own SMTP infrastructure.
Product memo
Developers who manage their own email infrastructure, such as Gmail, Amazon SES, or custom servers, use LetterStack to add a programmatic sending layer. It provides a REST API, Handlebars templating, and send logs, abstracting direct SMTP complexities. This approach kills the per-message fees of managed email providers.
For who
Developers bringing their own SMTP
Solves what
Provides an email API with templating and logs for custom SMTP setups
- Custom SMTP integration
- Handlebars templates
- REST send API
In their own words
Connect Gmail, Amazon SES, Zoho, or your own server and get Handlebars templates, a REST send API, and send logs without paying managed-provider m
Operator context
Operating setup
Founded
May 2026
HQ
Azerbaijan
Platform
API
Audience
Developers
Payments
Polar
Detected via TrustMRR
Builder Strategy
- Strategy Type
- Niche Specialist
- Stage
- Pre Revenue
- Effort
- Solo Buildable
About LetterStack Expand
LetterStack provides an email API for developers who prefer to use their existing SMTP infrastructure, such as Gmail, Amazon SES, Zoho, or private servers. It gives these users a REST API for sending, Handlebars templating for dynamic content, and detailed send logs for monitoring.
The focus on custom SMTP integration and developer-centric features makes it a specialized tool for teams seeking control and flexibility.