camunda-platform-7-mail

A community extension for Camunda Platform 7 to integrate emails in a process and interact with them. It was previously known as camunda-bpm-mail.

Features

• send mail
• poll mails
• delete mails
• react on incoming mails

Install

Requirements:

• Camunda Platform 7 >= 7.20.0
• Java 17

For Spring Boot

Read these instructions.

For Embedded Process Engine

Add camunda-bpm-mail-core as dependency to your application. Using Maven, you have to add the following lines to your POM:

<dependency>
  <groupId>org.camunda.bpm.extension</groupId>
  <artifactId>camunda-bpm-mail-core</artifactId>
  <version>1.5.1</version>
</dependency>

For Shared Process Engine

Add camunda-bpm-mail-core-1.5.1.jar to your application server (e.g. apache-tomcat-8.0.24\lib).

Also make sure that you included the following dependencies:

• camunda-connect-core >= 1.6.0
• JakartaMail >= 2.1.2
• Eclipse Angus Mail >= 2.0.2
• slf4j-api >= 2.0.11

If you use Wildfly, follow the special instructions.

How to use it?

The extension is build on top of the Connectors API and provide some connectors for interacting with emails. The connectors can be used inside a process as implementation of a service task and are referenced by id. Use the Camunda Modeler to configure it.

<serviceTask id="sendMail" name="Send Mail Task">
  <extensionElements>
    <camunda:connector>
      <camunda:connectorId>mail-send</camunda:connectorId>
      <!-- input / output mapping -->
    </camunda:connector>
  </extensionElements>
</serviceTask>

See the connectors user guide how to configure the process engine to use connectors.

Send Mails

Connector-Id: mail-send

Input parameter	Type	Required?
from	String	no (read from config)
fromAlias	String	no (read from config)
to	String	yes
cc	String	no
bcc	String	no
subject	String	yes
text	String	no
html	String	no
fileNames	List of String (path to files)	no
files	Map of String to file process variable	no

The text or html body can also be generated from a template (e.g. using FreeMarker). See the example.

Poll Mails

Connector-Id: mail-poll

Input parameter	Type	Required?
folder	String (e.g. 'INBOX')	no (read from config)
download-attachments	Boolean	no (read from config)

Output parameter	Type
mails	List of Mail

If download-attachments is set to true then it stores the attachments of the mails in the folder which is provided by the configuration. The path of the stored attachments can be gotten from the Attachments of the Mail.

By default, the polled mails are marked as read. If the property mail.imaps.peek is set to true then the mails are just polled and not marked as read.

Delete Mails

Connector-Id: mail-delete

Input parameter	Type	Required?
folder	String (e.g. 'INBOX')	no (read from config)
mails	List of Mail	no1
messageIds	List of String	no1
messageNumbers	List of Integer	no1

¹ Either mails, messageIds or messageNumbers have to be set.

React on incoming Mails

The extension provide the MailNotificationService to react on incoming mails (e.g. start a process instance or correlate a message). You can register handlers / consumers which are invoked when a new mail is received.

MailNotificationService notificationService = new MailNotificationService(configuration);

notificationService.registerMailHandler(mail -> {
  runtimeService.startProcessInstanceByKey("process",
    Variables.createVariables().putValue("mail", mail));
});

notificationService.start();

// ...

notificationService.stop();

If you use a mail handler and enabled downloadAttachments in the configuration then it stores the attachments of the mail before invoking the handler. Otherwise, you can also trigger the download manual by calling Mail.downloadAttachments().

How to configure it?

By default, the extension loads the configuration from a properties file mail-config.properties on classpath. You can change the lookup path using the environment variable MAIL_CONFIG. If you want to look up a file on the classpath, use the classpath: prefix (e.g. classpath:/my-application.config).

An example configuration can look like:

# send mails via SMTP
mail.transport.protocol=smtp

mail.smtp.host=smtp.gmail.com
mail.smtp.port=465
mail.smtp.auth=true
mail.smtp.ssl.enable=true
mail.smtp.socketFactory.port=465
mail.smtp.socketFactory.class=javax.net.ssl.SSLSocketFactory

# poll mails via IMAPS
mail.store.protocol=imaps

mail.imaps.host=imap.gmail.com
mail.imaps.port=993
mail.imaps.timeout=10000

# if peek = false then the polled mails are marked as read
mail.imaps.peek=false

# additional config
mail.poll.folder=INBOX
mail.sender=USER@google.com
mail.sender.alias=User Inc

mail.attachment.download=true
mail.attachment.path=attachments

# credentials
mail.user=USER@gmail.com
mail.password=PASSWORD

You can find some sample configurations at extension/core/configs. If you use a mail provider which has no configuration yet, feel free to add one. You can verify your configuration with the integration tests.

Alternative Configuration

if you are running camunda in the environment that supports Mail Service and Java Naming and Directory Interface (JNDI), you can configure mail session in the container and make it available through jndi. Provide the jndi-name of your bound mail session within properties file mail-config.properties like this:

mail.session.jndi.name=java:jboss/mail/MyMailSessionName

Please refer you container documentation to configure mail service.

If you do not need other properties then session configuration, you can even skip property file mail-config.properties and specify your mail session jndi-name directly via MAIL_CONFIG environment variable like this:jndi:java:jboss/mail/MyMailSessionName. Ensure it starts with jndi:

Examples

The following examples shows how to use the connectors and services.

• Pizza Order
  • poll mails
  • send mail with generated text body
  • delete mail
• Print Service
  • using the MailNotificationService
  • send mail with attachment

Setting up configuration using HELM

The mail connector cannot directly support Helm values files since it cannot assume the deployment environment is Kubernetes.

This is why it is configured via the MAIL_CONFIG environment variable and a properties file.

However, supporting Helm deployment is easily done by following:

1. Accept the mail configuration in your Values.yaml, like this:

   ...
   mail:
       smtp:
           auth: true
           port: 465
   ...
   

2. Render the mail.properties file with a Helm template

   mail.smtp.auth={{ .Values.mail.smtp.auth }}
   mail.smtp.port={{ .Values.mail.smtp.port }}
   

3. Put the mail.properties file in a ConfigMap and mount it in your deployment on /config/mail.properties (or anywhere else you prefer)

4. Set the MAIL_CONFIG environment variable to "file:/config/mail.properties" in your deployment

Next Steps

Depends on the input of the community. Some ideas:

• provide element templates for camunda modeler (not supported yet)
• integration of file process variables
• spring-based configuration

Contribution

Found a bug? Please report it using GitHub Issues.

Want to extend, improve or fix a bug in the extension? Pull Requests are very welcome.

Want to discuss something? The Camunda Forum might be the best place for it.

FAQ

See also

• JavaMail Project Documentation/FAQ
• Oracle JavaMail FAQ

Can't send / receive mails from Gmail

It can be that Google blocks the requests because it estimates your application as unsafe. You may also receive an email from Google. To fix this go to https://www.google.com/settings/security/lesssecureapps and enable less secure apps.

License

Apache License, Version 2.0