Unable To Send Test Email In vSphere Data Protection 6.x

Once you configure email settings in VDP, the first thing we do is send a test email to verify the configuration is good. The test email content should be something like:

However, you might come across an issue, where the test email does not trigger and you will see the following error in the web client:


In the vdr-server.log you can notice the following:

2017-06-07 01:46:27,636 ERROR [http-nio-8543-exec-9]-email.EmailBase: On try 0to send the email, recieved a connection error from the external email server:Could not connect to SMTP host: email.vmware.com, port:
 587
2017-06-07 01:46:27,636 ERROR [http-nio-8543-exec-9]-services.EmailConfigServiceWS: Unable to trigger test email
javax.mail.MessagingException: Could not connect to SMTP host: email.vmware.com, port: 587;
  nested exception is:
        java.net.ConnectException: Connection timed out (Connection timed out)
        at com.sun.mail.smtp.SMTPTransport.openServer(SMTPTransport.java:1282)
        at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:370)
        at javax.mail.Service.connect(Service.java:297)
        at javax.mail.Service.connect(Service.java:156)
        at javax.mail.Service.connect(Service.java:105)
        at javax.mail.Transport.send0(Transport.java:168)
        at javax.mail.Transport.send(Transport.java:98)
        at com.emc.vdp2.common.email.EmailBase.sendReport(EmailBase.java:174)
        at com.emc.vdp2.common.email.EmailBase.sendReport(EmailBase.java:63)
        at com.emc.vdp2.email.EmailSummaryReport.sendTestEmail(EmailSummaryReport.java:129)
        at com.emc.vdp2.services.EmailConfigServiceWS.runEmailTest(EmailConfigServiceWS.java:93)
        at com.emc.vdp2.rest.ReportService.runEmailTest(ReportService.java:241)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
        at java.lang.reflect.Method.invoke(Unknown Source)

Use SMTP port 25 to fix this issue.
So in the configuration of mail settings, in the field for Outgoing mail server, specify
<your mail sever > : 25

Note that there is <space> before and after the :
Save the settings and now the test email should work.

I believe port 587 is block on Firewall.base for VDP and explicitly mentioning 25 resolves this, as SMTP 25 is open on VDP.
You can netstat -ano | grep 25 and netstat -ano | grep 587

Hope this helps!