rest2smtp

Send mails via REST API

API documentation is served by the program under the root path (/). It's also available here.

Config

Env Var	Description
SMTP_HOST	Hostname (required)
SMTP_PORT	(default depends on encryption method)
SMTP_ENCRYPTION	TLS (default), STARTTLS, UNENCRYPTED (insecure)
SMTP_USERNAME	(optional)
SMTP_PASSWORD	(optional)
API_TOKEN	When set, HTTP request header Authorization: Bearer <token> must be present. (optional)
API_DOC_INFO	Custom text (or HTML) to be displayed in API documentation header. Defaults to "Send mails via REST API" (optional)

Deployment

Docker

docker run -p 8080:80 -e SMTP_HOST=smtp.example.org -e SMTP_USERNAME=user -e SMTP_PASSWORD=password knrdl/rest2smtp

Open the API documentation: http://localhost:8080/

curl -X POST http://localhost:8080/send -F 'subject=Test' -F 'content_html=Hi there' -F 'to_address=info@example.invalid'

Docker Compose

services:
  rest2smtp:
    image: knrdl/rest2smtp  # or alternative: ghcr.io/knrdl/rest2smtp
    hostname: rest2smtp
    environment:
      SMTP_HOST: smtp.example.org  # replace this
      # see config table above for optional settings
    ports:
      - "80:80"

NixOS

{ ... }:
{
  imports = [ ./path/to/rest2smtp/nix/module.nix ];

  services.rest2smtp = {
    enable = true;
    port = 8080;
    smtp = {
      host = "smtp.example.org";
      # username = "user";
      # passwordFile = "/etc/rest2smtp.pass";
    };
    # Optional: require Authorization: Bearer <token> on POST /send
    # apiTokenFile = "/etc/rest2smtp.token";
  };
}

Build the package from this repository (no GitHub source fetch):

nix-build -E 'with import <nixpkgs> {}; callPackage ./nix/package.nix {}'

Manual build

# in project root dir
docker run -it --rm -v "$PWD:$PWD" -w "$PWD" -p8080:80 --env-file env docker.io/library/rust
$ cargo run