MailDrop

See MailDrop in action.

MailDrop is an open-source, scalable, high-performance version of Mailinator, a "temporary inbox" that you can give out when you don't want to give out your real e-mail address. MailDrop inboxes are designed to be quick and disposable.

The design goals are to be roughly 90% of the speed of Mailinator, while adding additional functionality and the ability to horizontally scale quickly and easily.

Where Mailinator runs within one JVM, MailDrop splits the SMTP and web applications into separate JVMs, while using Redis as its main data store. This allows for a more fluid application architecture, while still retaining the speed expected for a high-speed mail and web app.

MailDrop is written in Scala, with heavy use of Akka actors and the Play Framework. Functionality includes:

• Antispam modules contributed from Heluna for senders and data
• 90% of all spam attempts rejected
• Network blacklists
• IP connection and message subject limiting
• Reputation-based blocking
• SPF checking
• Greylisting
• Alternate inbox aliases
• Strip message attachments
• Message size limits
• SMTP configuration done in one file
• Easy-to-modify website, written in LESS and CoffeeScript

Requirements

• SBT 0.13+
• PlayFramework 2.3.4+
• Redis 2.6+

For hardware, an Amazon EC2 small instance should be good to begin. MailDrop should take 512M of RAM for the SMTP module, 512M of RAM for the web module, and 512M of RAM for the Redis datastore. In practice, CPU is not an issue; MailDrop spends most of its time waiting on disk or network IO.

Installation

Clone the repository into a local directory

This will give you three subdirectories, "common" is the shared set of utility classes and models, "smtp" is the mail transfer agent, and "web" is the website.

Create the SMTP server

Go into "smtp" and run "sbt compile". This will create a jar of the MailDrop SMTP server. If you like, you can create a single jar with all dependencies included by running "sbt assembly".

To run the SMTP server, use "java -jar (jarfile) MailDrop". If you want to use a custom configuration, use "java -Dconfig.file=/path/to/your/application.conf -jar (jarfile) MailDrop".

Create the web server

Go into "web" and run "activator dist". This will create a zipfile of the MailDrop website. (More information about how to run a Play web app is located on the Play Framework site)

To run the web server, simply use the "start" command inside the zipfile, or again to specify a custom configuration use start -Dconfig.file=/path/to/your/application.conf

Create start scripts with file logs

##Create folder for logs

Mkdir /var/log/maildrop

Go to the Maildrop root foler and create a new file:

echo "setsid nohup java -Dconfig.file=/opt/maildrop/smtp/smtp.conf -jar /opt/maildrop/smtp/smtp-server.jar MailDrop &>>/var/log/maildrop/smtp.log>&1&" >  ./start-smtp.sh

Point Dconfig.file to the smtp server config & -jar to the smtp-assembly-2.0.jar file

echo "setsid nohup /opt/maildrop/web-2.0/bin/web -Dconfig.file=/opt/maildrop/web-2.0/conf/application.conf &>/var/log/maildrop/web.log>&1&" > ./start-web.sh

Have it execute web-2.0/bin/web with Dconfig.file pointing to the conf/application.conf, use full addresses if you want to create a service.

sudo chmod +x ./start-*

Create system services for automated start / easy start/stop

This will create a service file to run MailDrop's SMTP server

echo "[Unit]
Description=maildrop-smtp
After=network.target redis.service
 
[Service]
User=root
ExecStart=/bin/bash -c "java -Dconfig.file=/opt/maildrop/smtp/smtp.conf -jar /opt/maildrop/smtp/smtp-server.jar >MailDrop>>/var/log/maildrop/smtp.log" 
 
[Install]
WantedBy=multi-user.target
">/etc/systemd/system/maildrop-smtp.service

This will create a service file to run MailDrop's WEB server

echo "[Unit]
Description=maildrop-web
After=network.target redis.service

[Service]
User=root
ExecStart=/bin/bash -c "/opt/maildrop/web-2.0/bin/web -Dconfig.file=/opt/maildrop/web-2.0/conf/application.conf &>>/var/log/maildrop/web.log"

[Install]
WantedBy=multi-user.target
">/etc/systemd/system/maildrop-web.service

Reload the services daemon to see the new files, and start them on boot

systemctl daemon-reload
systemctl enable maildrop-smtp.service
systemctl enable maildrop-web.service

Setup log rotation for file logs

sudo nano /etc/logrotate.d/maildrop.conf
/var/log/maildrop/*.log {
    daily # rotate daily
    size 10240 # rotate if 10MB or larger
    minsize 1024 # Do not rotate if under 1MB
    notifempty # Do not rotate if empty
}

Obviously you can set your own rules on rotation

Ctrl + X -> Y to save

Changelog

Version 2.0 is a rewrite of the internals of MailDrop. The site itself has the same look and feel, but the way messages are dealt with is slightly different.

The primary change is a switch to rediscala to connect to the Redis instance. rediscala is a Reactive driver and performs much better than the old Redis client.

Next, many of the actors and supervisors have been tossed in favor of simple Scala futures. This has simplified the codebase while still allowing for high performance-- MailDrop just won't be able to be as finely tuned (custom dispatchers, guaranteed message delivery, etc).

Messages are now stored in Redis in json format instead of as serialized ByteStrings. The overhead of json parsing on the website is minimal and allows for a better overall view of the data inside Redis.

Last, Play has been updated to the 2.3 branch, along with automatic asset versioning and a much cleaner way to cache assets. Website performance should be increased vs. the previous version of MailDrop.