Email Event Publisher

Email event publisher is used to publish events in XML, JSON or text formats via email transports.

Prerequisites

Follow the steps below to complete the prerequisites before starting the event publisher configurations.

Edit the email address, username, password and other relevant properties in the <PRODUCT_HOME>/repository/conf/output-event-adapters.xml file, to point the mail transport sender which is enabled by default in the product, to a valid SMTP configuration as shown in the example below.

<adapterConfig type="email">
    <property key="mail.smtp.from">email-address</property>
    <property key="mail.smtp.user">user-name</property>
    <property key="mail.smtp.password">password</property>
    <property key="mail.smtp.host">smtp.gmail.com</property>
    <property key="mail.smtp.port">587</property>
    <property key="mail.smtp.starttls.enable">true</property>
    <property key="mail.smtp.auth">true</property>
    <!-- Thread Pool Related Properties -->
    <property key="maxThread">100</property>
    <property key="keepAliveTimeInMillis">20000</property>
    <property key="jobQueueSize">10000</property>
</adapterConfig>

In gmail account security settings you may have to enable "Allow less secure apps" option in order to connect account to WSO2 products.
When SMTP is used with SSL, it is required to extract the certificate of the email server and add it to the trust store of WSO2 DAS. For detailed instructions, see Creating New Keystores - Adding the public key to client-truststore.jks.

Creating an email event publisher

For instructions on creating an email event publisher, see Configuring CEP to Create Alerts.

Configuring global properties

The following global properties can be set for the Email event publisher type in the <CEP_HOME>/repository/conf/input-event-adapters.xml file. These properties apply to all the publishers of the email type. If a global property available by default is removed, the default value of the property is considered.

Custom properties cannot be added as global properties.

Property Key	Description	Data Type	Default Value
`mail.smtp.from`	The email address used by the publisher to publish events.	String	`abcd@gmail.com`
`mail.smtp.user`	The username used by the publisher to publish events via email.	String	`abcd`
`mail.smtp.password`	The password used by the publish events via email.	String	xxxx
`mail.smtp.host`	The host of the email server.	String	`smtp.gmail.com`
`mail.smtp.port`	The port of the email server.	Integer	`587`
`mail.smtp.starttls.enable`	This property specifies whether STARTTLS encryption is enabled or not. STARTTLS is an extension which enables a plain text connection to be upgraded to an encrypted (SSL or TLS) connection.	Boolean	`true`
`mail.smtp.auth`	This property specifies whether SMTP authentication is enabled or not.	Boolean	`true`
`minThread`	The minimum number of threads (including idle threads) that should be available in the thread pool at a given time.	Integer	`8`
`maxThread`	The maximum number of threads (including idle threads) that should be available in the thread pool at a given time.	Integer	`100`
`keepAliveTimeInMillis`	The maximum number of milliseconds that idle threads should be kept alive when the total number of threads in the pool exceeds the number of cores in the machine.	Integer	`20000`
`jobQueueSize`	The maximum number of milliseconds that idle threads should be kept alive when the total number of threads in the pool exceeds the number of cores in the machine.	Integer	`10000`

Configuring adapter properties

Specify the Dynamic Adapter Properties, when creating an email event publisher using the management console as shown below. For Dynamic properties user can choose to add placeholders({{placeholder}}) so that value of the dynamic properties will be based on event values in run-time. As an example, as the value of 'Email Address' property user can provide {{email_address_attribute}}.

email event publisher

After entering the above adapter properties, select the Message Format which you want to apply on the published events. Also, click Advanced to define custom output mappings based on the Message Format you selected. For more information on custom output mapping types, see Output Mapping Types.

You can also define the respective adapter properties of the event publisher based on the transport type within the <to> element of the event publisher configuration in the <PRODUCT_HOME>/repository/deployment/server/eventpublishers/ directory as follows.

<eventPublisher name="EmailOuputEventAdapter" statistics="disable" trace="disable" xmlns="http://wso2.org/carbon/eventpublisher">
 ...................
  <to eventAdapterType="email">
    <property name="email.address">user@gmail.com</property>
    <property name="email.type">text/plain</property>
    <property name="email.subject">This is a test mail.</property>
  </to>
</eventPublisher>

The above adapter properties are described below.

Adapter Property	Description	Configuration file property	Example
Email Address	Email address of the client. Register the publisher for multiple email IDs' by separating them with commas.	email.address	`user@gmail.com`
Subject	Subject of the email to be sent to the defined email address	email.subject	`This is a test mail.`
Email Type	The email format to be sent to the defined email address. If you select `text/html` for this parameter, the message body should be in valid HTML.	email.type	`text/plain`

Related samples

For more information on email event publisher type, see the following sample.

Sample 0064 - Publishing Text Events via Email Transport