Sending Authenticated Email

This is an analysis of the work needed to enable CSF-based apps to send authenticated email.

Changes to CSF:

1. Configuration of mailSender Spring Bean

Configure mailSender bean to use additional properties. Currently only uses "host" = "outgoing.mit.edu". This would be a modification to applicationContext-csf-email-scheduler.xml in the csf-email module. The additional properties are:

<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
  <property name="host" value="outgoing.mit.edu"/>
  <property name="port" value="587"/>
  <property name="username" value="USERNAME"/>
  <property name="password" value="PASSWORD"/>
  <property name="javaMailProperties">
    <props>
      <prop key="mail.debug">false</prop>
      <prop key="mail.smtp.auth">true</prop>
      <prop key="mail.smtp.starttls.enable">true</prop>
    </props>
  </property>
</bean>

The username, password, port, and possibly host, property values should be externalized to a properties file. We can put these properties in machine.properties - apps should pick this up automatically. Only one copy of this props file per server.

Any app that needs to use this feature would have to upgrade its version of CSF and be retested. Each app would also need to reviewed to make sure it uses "machine.properties" in its property configuration.

2.One Login Per Batch of Email Messages

One question - for a bulk email send, should we authenticate to the server for every single email message in the batch:

DO FOR EACH MAIL MESSAGE
    authenticate to server    send email message
END DO

or just once for the batch:

authenticate to serverDO FOR EACH MAIL MESSAGE
    send email message
END DO

My initial test with CSF does the former. WTW seems to do the latter.

The latter seems better (only one login per batch rather than one login per message). To do this, the email service needs to change - in fact it may be better to change it anyway. In "batchSend", instead of:

Get list of email events
DO FOR each email event
  create MimeMessagePreparator
  send message using MimeMessagePreparator
  update email event
END DO

do this:

Get list of email events
DO FOR each email event
  create MimeMessagePreparator and store in list
END DO

send messages using list of MimeMessagePreparators
update email events

We would use the "batch" API of Spring's JavaMailSender API:

send(MimeMessagePreparator[] mimeMessagePreparators)

instead of

send(MimeMessagePreparator mimeMessagePreparator)

Summary

This change would mean:

1. Modifications to csf-email (detailed above)
2. Changes to common property files (i.e. machine.properties) on each server that hosts CSF web apps.
3. Build & release of each web app that needs to use this feature.
4. Retest of each rebuilt app.