Golang SMTP server
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README.md

tmail

Join the chat at https://gitter.im/toorop/tmail

tmail is a SMTP server

Features

  • SMTP, SMTP over SSL, ESMTP (SIZE, AUTH PLAIN, STARTTLS)
  • Advanced routing for outgoing mails (failover and round robin on routes, route by recipient, sender, authuser... )
  • SMTPAUTH (plain & cram-md5) for in/outgoing mails
  • STARTTLS/SSL for in/outgoing connexions.
  • Manageable via CLI or REST API.
  • DKIM support for signing outgoing mails.
  • Builtin support of clamav (open-source antivirus scanner).
  • Builtin Dovecot (imap server) support.
  • Fully extendable via plugins
  • Easy to deploy
  • No dependencies: -> you do not have to install nor maintain libs
  • Clusterisable (todo)
  • IPV6 (soon)

Quick install on linux (Ubuntu)

For french users see: http://tmail.io/doc/installer-tmail/

add user tmail

adduser tmail

Fetch tmail dist

# su tmail
$ cd
$ wget ftp://ftp.toorop.fr/softs/tmail/tmail.zip
$ unzip tmail.zip
$ cd dist

Under dist you will find:

  • conf: configuration.
  • run: script used to launch tmail
  • ssl: is the place to store SSL cert. For testing purpose you can use those included.
  • tmail: tmail binary
  • tpl: text templates.
  • db: if you use sqlite as DB backend (MySQL and Postgresql are also supported), sqlite file will be stored in this directory.
  • store: mainly used to store raw email when they are in queue. (others kind of backend/storage engine are coming)
  • mailboxes: where mailboxes are stored if you activate Dovecot support.

Make run script and tmail runnable:

chmod 700 run tmail

add directories:

mkdir db
mkdir store

if you want to enable Dovecot support add mailboxes directory:

mkdir mailboxes

See Enabling Dovecot support for tmail (french) for more info.

Configuration

Init you conf file:

cd conf
cp tmail.cfg.base tmail.cfg
chmod 600 tmail.cfg
  • TMAIL_ME: Hostname of the SMTP server (will be used for HELO|EHLO)

  • TMAIL_DB_DRIVER: I recommend sqlite3 unless you want to enable clustering (or you have a lot of domains/mailboxes)

  • TMAIL_SMTPD_DSNS: listening IP(s), port(s) and SSL options (see conf file for more info)

  • TMAIL_DELIVERD_LOCAL_IPS: IP(s) to use for sending mail to remote host.

  • TMAIL_SMTPD_CONCURRENCY_INCOMING: max concurent incomming proccess

  • TMAIL_DELIVERD_MAX_IN_FLIGHT: concurrent delivery proccess

Init database

tmail@dev:~/dist$ ./run
Database 'driver: sqlite3, source: /home/tmail/dist/db/tmail.db' misses some tables.
Should i create them ? (y/n): y

[dev.tmail.io - 127.0.0.1] 2015/02/02 12:42:32.449597 INFO - smtpd 151.80.115.83:2525 launched.
[dev.tmail.io - 127.0.0.1] 2015/02/02 12:42:32.449931 INFO - smtpd 151.80.115.83:5877 launched.
[dev.tmail.io - 127.0.0.1] 2015/02/02 12:42:32.450011 INFO - smtpd 151.80.115.83:4655 SSL launched.
[dev.tmail.io - 127.0.0.1] 2015/02/02 12:42:32.499728 INFO - deliverd launched

Port forwarding

As you run tmail under tmail user, it can't open port under 1024 (and for now tmail can be launched as root, open port under 25 and fork itself to unprivilegied user).

The workaround is to use iptables to forward ports. For example, if we have tmail listening on ports 2525, and 5877 and we want tu use 25 and 587 as public ports, we have to use those iptables rules:

iptables -t nat -A PREROUTING -p tcp --dport 25 -j REDIRECT --to-port 2525
iptables -t nat -A PREROUTING -p tcp --dport 587 -j REDIRECT --to-port 5877

First test

$ telnet dev.tmail.io 25
Trying 151.80.115.83...
Connected to dev.tmail.io.
Escape character is '^]'.
220 tmail.io  tmail ESMTP f22815e0988b8766b6fe69cbc73fb0d965754f60
HELO toto
250 tmail.io
MAIL FROM: toorop@tmail.io
250 ok
RCPT TO: toorop@tmail.io
554 5.7.1 <toorop@tmail.io>: Relay access denied.
Connection closed by foreign host.

Perfect ! You got "Relay access denied" because by default noboby can use tmail for relaying mails.

Relaying mails for @example.com

If you want tmail to relay mails for example.com, just run:

tmail rcpthost add example.com

Note: If you have activated Dovecot support and example.com is a local domain, add -l flag :

tmail rcpthost add -l example.com

Does it work as expected ?

$ telnet dev.tmail.io 25
Trying 151.80.115.83...
Connected to dev.tmail.io.
Escape character is '^]'.
220 tmail.io  tmail ESMTP 96b78ef8f850253cc956820a874e8ce40773bfb7
HELO toto
250 tmail.io
mail from: toorop@toorop.fr
250 ok
rcpt to: toorop@example.com
250 ok
data
354 End data with <CR><LF>.<CR><LF>
subject: test tmail

blabla
.
250 2.0.0 Ok: queued 2736698d73c044fd7f1994e76814d737c702a25e
quit
221 2.0.0 Bye
Connection closed by foreign host.

Yes ;)

Allow relay from an IP

tmail relayip add IP

For example:

tmail relayip add 127.0.0.1

Basic routing

By default tmail will use MX records for routing mails, but you can "manualy" configure alternative routing. If you want tmail to route mail from @example.com to mx.slowmail.com. It is as easy as adding this routing rule

tmail routes add -d example.com -rh mx.slowmail.com

You can find more elaborated routing rules on tmail routing documentation (french) (translators are welcomed ;))

SMTP AUTH

If you want to enable relaying after SMTP AUTH for user toorop@tmail.io, just enter:

tmail user add -r toorop@tmail.io password

If you want to delete user toorop@tmail.io :

tmail user del toorop@tmail.io

Let's Encrypt (TLS/SSL)

If you want to activate TLS/SSL connections with a valid certificate (not an auto-signed one as it's by default) between mail clients and your tmail server you can get a let's Encrypt certificate, you have first to install let's Encrypt :

cd ~
git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt

Then you can request a certificate

./letsencrypt-auto certonly --standalone -d your.hostname

You'll have to provide a valid mail address and agree to the Let's Encrypt Term of Service. When certificate is issued you have to copy some files to the ssl/ directory

cd /home/tmail/dist/ssl
cp /etc/letsencrypt/live/your.hostname/fullchain.pem server.crt
cp /etc/letsencrypt/live/your.hostname/privkey.pem server.key
chown tmail.tmail server.*

And it's done !

Contribute

Feel free to inspect & improve tmail code, PR are welcomed ;)

If you are not a coder, you can contribute too:

  • install and use tmail, I need feebacks.

  • as you can see reading this page, english is not my native language, so I need help to write english documentation.

Roadmap

  • clustering
  • IPV6
  • write unit tests (yes i know...)
  • improve, refactor, optimize
  • test test test test

License

MIT, see LICENSE

Imported packages

github.com/nsqio/nsq/... github.com/codegangsta/cli github.com/codegangsta/negroni github.com/go-sql-driver/mysql github.com/jinzhu/gorm github.com/julienschmidt/httprouter github.com/kless/osutil/user/crypt/... github.com/lib/pq github.com/mattn/go-sqlite3 github.com/nbio/httpcontext golang.org/x/crypto/bcrypt golang.org/x/crypto/blowfish