How do I deploy Mini Mailer on Railway?

You can deploy Mini Mailer on Railway by clicking the "Deploy Now" button on this page. Railway will automatically set up all the necessary services and configurations for you.

What are the system requirements?

Railway handles all the infrastructure requirements. You only need a web browser to deploy and manage your application.

Is this template free to use?

Yes, this template is free to use within your existing Railway account.

Can I customize this template?

Yes, you can fully customize this template. After deployment, you will have full control of what you've deployed in your Railway project.

How do I get support for this template?

You can get support through our community forum: mini-mailer-ec42d059, or click "Get template help" for this template for more assistance.

Deploy and Host Mini Mailer on Railway

Mini Mailer is a simple SMTP server that forwards mail over HTTP to Mailgun, Postmark, or MailerSend. For use as an SMTP gateway to allow applications that use SMTP to send emails via an HTTP endpoint when outbound SMTP is restricted.

Mini Mailer does not currently support attachments and is designed to run on an internal network only (e.g. mini-mailer.railway.internal), as it does not use TLS.

About Hosting Mini Mailer

Mini Mailer is a simple serverless application that creates an SMTP server on ports 25, 2525, and 587, and a HTTP server on port 80 used for health checks. The SMTP server listens for incoming SMTP connections and forwards the email to the HTTP endpoint.

Mini Mailer requires no configuration or dependencies and will automatically detect the email service provider based on the API token used.

To send emails, configure your application to send email with:

Host: your Mini Mailer host (e.g. mini-mailer.railway.internal).
Port: 25, 2525, or 587.
Username: For Mailgun, this is the domain name (e.g. mg.yourdomain.com). For Postmark and MailerSend, this is any username.
Password: Your email service provider's API key or token.

Common Use Cases

Relaying SMTP traffic to HTTP endpoints
Sending SMTP email when outbound SMTP is restricted

API Keys and Endpoints

Mailgun

Create a new Domain Sending Key for your domain. Use your domain (or any email address on the sending domain) as the SMTP username, and the API key as the SMTP password.

Internally, Mini Mailer will use the API endpoint https://api.mailgun.net/v3/{domain}/messages.mime to send emails.

Postmark

Create a new Server API Token for your server. Use any username as the SMTP username, and the API token as the SMTP password.

Internally, Mini Mailer will use the API endpoint https://api.postmarkapp.com/email to send emails.

MailerSend

Create a new API Token for your account. Use any username as the SMTP username, and the API token as the SMTP password.

Internally, Mini Mailer will use the API endpoint https://api.mailersend.com/v1/email to send emails.

Dependencies for Mini Mailer Hosting

One of the following email service providers:

Mailgun
Postmark
MailerSend

Deployment Dependencies

Environment Variables:

PORT: Health check port (80)

Why Deploy Mini Mailer on Railway?

Railway is a singular platform to deploy your infrastructure stack. Railway will host your infrastructure so you don't have to deal with configuration, while allowing you to vertically and horizontally scale it.

By deploying Mini Mailer on Railway, you are one step closer to supporting a complete full-stack application with minimal burden. Host your servers, databases, AI agents, and more on Railway.