RabbitMQ-SMTP, a Legacy SMTP receiver plugin for RabbitMQ

Legacy Software Warning

rabbitmq-smtp has not seen updates in more than 3 years and will not work with recent versions of RabbitMQ.

It has since been superseded by rabbitmq-email. Please consider using that project first.

What It Does

The RabbitMQ-SMTP plugin listens on a configurable TCP port for incoming email message traffic, and routes the traffic on via RabbitMQ's exchanges.

There is no support at this time for sending outgoing email from RabbitMQ.

Building the plugin

You will need:

• a recent Erlang
• a setup for building RabbitMQ plugins. Please see the instructions for setting this up.

Once you are able to build the server and its plugins, you can build the SMTP plugin. Within the rabbitmq-public-umbrella directory,

hg clone http://hg.rabbitmq.com/rabbitmq-smtp
cd rabbitmq-smtp
make

At this point, the Makefile will retrieve a copy of erlang-smtp if it hasn't done so already. It will then compile everything, resulting (if all goes well) in the presence of rabbitmq-smtp/dist/rabbitmq-smtp.ez and rabbitmq-smtp/dist/erlang-smtp.ez. The plugins can then be activated as per the instructions.

Mapping between SMTP and AMQP

When an email arrives at the adapter, its SMTP "To" address is examined to determine how it should be routed through the system. First, the address is split into a mailbox name and a domain part. The mailbox name is then split at the first hyphen into two pieces.

• the domain part (e.g. "@rabbitmq.com") is used to map to an AMQP virtual-host
• if the mailbox name contained a hyphen,
  • the first part of the name is mapped to an AMQP exchange name, and
  • the second part is mapped to an AMQP routing key
• otherwise, if no hyphen was present in the mailbox name, the whole mailbox name is used as the AMQP exchange name, and the AMQP routing key is set to the empty string.

For example, [email protected] is mapped to

• the virtual host configured in the vhost_map (see below on configuration) for rabbitmq.com
• the exchange "tonyg"
• the routing key ""

and [email protected] is mapped to

• the virtual host configured in the vhost_map for rabbitmq.com
• the exchange "tonyg"
• the routing key "foo"

Configuring the plugin

The plugin is configured using the normal Erlang application configuration mechanism. RabbitMQ has a standard configuration file that can be used to configure the plugin. The application name is rabbitmq_smtp_server, and the individual keys are described below.

Here is an example snippet of a RabbitMQ configuration file containing rabbitmq_smtp_server settings:

...
{rabbitmq_smtp_server, vhost_map, [{"localhost", <<"/">>}]},
{rabbitmq_smtp_server, default_vhosts, true},
{rabbitmq_smtp_server, listen_port, 8025},
...

Configuring the way SMTP domains are mapped to AMQP virtual-hosts

Two configuration variables control this process. The first, vhost_map, should be set to a list of tuples with the first element set to a string for the domain to map from, and the second element set to a binary for the virtual-host to map to. For example, the default value for vhost_map is

[{"localhost", <<"/">>}]

which maps the SMTP "@localhost" domain onto the usual preconfigured virtual-host "/".

In cases where the plugin searches for a domain in the vhost_map but cannot find one, the second configuration variable, default_vhosts is consulted. If it is set to the atom true, then the SMTP domain is used directly as the name of the AMQP virtual-host. If it is set to the atom false, then the plugin will instead return an error for uses of the missing domain.

Configuring the IP address and port number that the plugin listens on

Two configuration variables are used here:

• listen_host, which should be set to a string containing an IP address. The default setting is "0.0.0.0".

• listen_port, which should be set to an integer containing a TCP port number. The default setting is 8025.

Example session

(tbd)

Copyright and Licensing

Copyright (c) 2007--2010 Tony Garnock-Jones [email protected] Copyright (c) 2007--2010 LShift Ltd. [email protected]

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.