EmailEngine Email API

NB This is the version 2 of EmailEngine. If you are looking for the previous version, you can find it here.

Headless email client that makes IMAP and SMTP resources available over REST. Integrate email accounts with your service with ease!

• Documentation and details: EmailEngine.app
• Discord chat room

Use cases

• Syncing users' emails to your service and sending out emails on behalf of your users
• Integrating your app with a specific email account, eg. your support email
• Monitor INBOX and Junk folders of a test email account to see where the emails you send out end up in
• Lightweight webmail and mobile email apps that do not want to process IMAP and MIME

Quickstart

This example assumes that Redis is installed locally and does not require any authentication. See docs for other options.

1. Download EmailEngine for your OS:

   • MacOS
   • Linux
   • Window
   • Docker: docker pull andris9/emailengine:v2

2. Open http://127.0.0.1:3000 in your browser

Later, when you want to upgrade, just download the newer version and restart the emailengine service.

Tip For human readable logs you can use pino-pretty (npm install -g pino-pretty) by piping EmailEngine output to it: emailengine | pino-pretty

Run on Heroku

Screenshots

Version and license

Run the following command to see the version and license information both for EmailEngine and for the included modules.

$ emailengine license

Requirements

• Redis – any version

There is no official Redis release for Windows but you can use an alternative like Memurai.

Tip! Try to keep the latency between EmailEngine and Redis as low as possible, best if these would run in the same machine or at least in the same DC. EmailEngine runs a separate Redis command for each message in a folder when syncing messages, so if the latency is not low then it takes a long time to sync a folder with a lot of messages,

Documentation

• API Reference
• Blog posts
• For Postman you can import OpenAPI specification here.

Configuring EmailEngine

See the documentation for configuring EmailEngine here.

App access

By default EmailEngine allows connections only from localhost. To change this either edit config file or use --api.host="0.0.0.0" cli option. This would enable outside access, so you should use firewall or a proxy to only allow trusted sources.

Deployment

Ubuntu or Debian

You can use the included install script to set up

• EmailEngine as a SystemD service
• Nginx reverse proxy
• ACME.sh and Let's Encrypt HTTPS certoficate

$ wget https://raw.githubusercontent.com/postalsys/emailengine/master/install.sh
$ chmod +x install.sh
$ ./install.sh example.com info@example.com

Where

• example.com is the domain name for EmailEngine
• info@example.com is your email address to generate the HTTPS certificate

NB! Tested with Ubuntu 20.04 and Debian 11. Might not work with other OS versions.

SystemD

Read about running EmailEngine as a SystemD service here

Docker

See the documentation for using EmailEngine with Docker here.

Resolving issues with Redis

EmailEngine is using Redis as it's data store. Redis stores everything in RAM so if something weird happens, EmailEngine could flood Redis and make the app unusable once there is no available space left.

First thing to do is to check what is actually going on. EmailEngine provides a few tools for that:

1. Check Bull queues in Redis. You can use the built in Bull Arena UI to view the state of the queues. Open http://127.0.0.1:3000/admin/arena in your browser to see the queues.
2. Scan the used keyspace. EmailEngine provides a tool that groups keys by type. Run it like this (use the same config for DB as you are using for the main app):

$ emailengine scan > keyspace.csv

Monitoring

There is a Prometheus output available at /metrics URL path of the app.

Log analysis

Read about logging options here

Security and Data compliance

Read here.

Licensing

Dual licensed under GNU Affero General Public License v3.0 or later and the EmailEngine License.