Pretendo Network Email Forwarder

This is an SMTP server that forwards emails sent to a recipient of the form <pid>@domain to the associated PNID's real email address via SES.

Why?

This exists for several reasons involving PNID SSO:

• The Pretendo Network forum runs on Discourse, which requires every user to have a unique email address. However, Pretendo allows multiple PNIDs to share an email address, which means that multiple PNIDs would end up pointing to the same forum account (discussed here). To ensure that every forum account gets a unique email address, Discourse account emails are set to <pid>@domain during SSO, which means that forwarding is required for email notifications.
• The Pretendo Network ticketing system SSO will use these fake emails to keep users' real email addresses private from agents.

This server forwards emails sent to the fake email addresses provided via SSO to the associated PNID's real email address.

Setup

Running in Docker

1. Install Docker.
2. Copy the contents of example.env to a .env file and set up the environment variables (see Configuration).
3. Run docker run --env-file .env -p PORT:PORT ghcr.io/pretendonetwork/email-forwarder to start the server, replacing PORT with the SMTP port that you specified in the environment variables.

Running locally

1. Install Node.js.
2. Clone this repository.
3. Copy example.env to .env and set up the environment variables (see Configuration).
4. Run npm install to install dependencies.
5. Run npm run build to compile the TypeScript.
6. Run npm start to start the server.

Configuration

This server is configured via environment variables:

Name	Description	Default
PN_EMAIL_FORWARDER_SMTP_HOSTNAME	Hostname of the SMTP server, sent to the client for identification and logged in the added Received header	undefined (uses system hostname)
PN_EMAIL_FORWARDER_SMTP_PORT	Port that the SMTP server listens on	25
PN_EMAIL_FORWARDER_SMTP_USERNAME	Username for SMTP client authentication	N/A (required)
PN_EMAIL_FORWARDER_SMTP_PASSWORD	Password for SMTP client authentication	N/A (required)
PN_EMAIL_FORWARDER_SES_REGION	SES region	us-east-1
PN_EMAIL_FORWARDER_SES_ACCESS_KEY	SES access key	N/A (required)
PN_EMAIL_FORWARDER_SES_SECRET_KEY	SES secret key	N/A (required)
PN_EMAIL_FORWARDER_GRPC_ACCOUNT_ADDRESS	Address of the Pretendo Network account server	N/A (required)
PN_EMAIL_FORWARDER_GRPC_ACCOUNT_PORT	Port of the account server's gRPC service	N/A (required)
PN_EMAIL_FORWARDER_GRPC_ACCOUNT_API_KEY	API key for the account server's gRPC service	N/A (required)
PN_EMAIL_FORWARDER_DOMAINS_DEFAULT_ACTION	Default action for email sent to addresses with domains not specified in any of the below options, can be forward, passthrough, or drop	drop
PN_EMAIL_FORWARDER_DOMAINS_FORWARD	Emails sent to any address with a domain listed here will be treated as though the recipient is a PNID's fake email address and forwarded from <pid>@domain to the associated PNID's real email address	None
PN_EMAIL_FORWARDER_DOMAINS_PASSTHROUGH	Emails sent to any address with a domain listed here will be forwarded without modification to the recipient	None
PN_EMAIL_FORWARDER_DOMAINS_DROP	Emails sent to any address with a domain listed here will be silently dropped	None

See example.env for a full example configuration.