smtporter

README

SMTPorter

SMTPorter is a configurable SMTP proxy that aims to allow easy routing of e-mails to different providers. It is also capable of handling errors by using other configured providers as a fallback.

A minimalist web UI is provided for managing e-mail providers.

SMTPorter is still under active development.

Some features may be missing or not function exactly as expected. As such, use in production is to be done at your own risk. Read more at caveats & limitations.

Usage

You can use SMTPorter in a container via Docker, Podman, Kubernetes, etc. or build it from source.

Container image

For simplicity, the following example relies on Docker.

If you’re using podman, replace docker in the following commands with podman. It should work the same as Docker, but I haven’t yet tested this.

# Using the "latest" tag is a bad practice and is only given as an example
docker run -e WEB_AUTH_PASSWORD='ChangeMe!' quay.io/seizeheures/smtporter:latest

To use the base plugins I provide, use the tag <version>-plugins.

From source

Requirements:

• Go 1.21+

To compile from source, clone this repository and compile with:

go build cmd/smtporter.go

To start SMTPorter, run:

WEB_AUTH_PASSWORD="ChangeMe!" ./smtporter

Environment variables

Some configuration options can be set via the following environment variables:

Variable	Default	Explanation
WEB_AUTH_PASSWORD	N/A	Authentication password for the web interface. This parameter is required!
WEB_LISTEN_PORT	8080	Port on which to run the web server
SMTP_LISTEN_PORT	1025	Port on which to run the SMTP server
SMTP_AUTH_PASSWORD	N/A	Optional authentication password for the SMTP server, to be used with AUTH PLAIN by clients.
BASE_URL	localhost:8080	Web interface base URL, used for URL generation
ENABLE_FAILOVER	false	Whether or not to use other configured providers as fallback if sending via selected provider fails
ENABLE_WEBHOOK_LISTENER	false	Enable webhook functionality. See plugins for more information.

What's up with the name?

SMTPorter is named after porters, people who carry cargo to remote locations.

Caveats and limitations

The following is a list of caveats and limitations of SMTPorter, most of which are meant to be fixed or improved upon before 1.0.0.

• Providers cannot be deleted via the web interface.
• Multiple providers cannot be selected to be used in a round-robin strategy.
• HTML template files are not currently embedded in the binary. This isn’t a problem if using the container image, but if building from source you will need the templates/ folder in the same directory as the binary.
• SMTPorter has not yet been benchmarked.

License

SMTPorter is available as open source under the terms of the AGPLv3 License.

Documentation

Index

• type Config

Types

type Config

type Config struct {
	SMTPListenPort   uint32
	SMTPAuthPassword string
	WebListenPort    uint32
	WebAuthPassword  string
	DatabasePath     string
	BaseURL          string
	Failover         bool
	WebhookListener  bool
}