Outgoing email server configuration

Been trying to setup the outgoing email configuration, but it fails. I'm using Rackspace hosted email and I've keyed the configuration into the User Console. I've been able to locate the email config in an XML file and it looks exactly as I've keyed it and is as follows;

<?xml version="1.0" encoding="utf-8"?>
<email-smtp>
<properties>
<mail.smtp.host>secure.emailsrvr.com</mail.smtp.host>
<mail.smtp.port>465</mail.smtp.port>
<mail.transport.protocol>SMTP</mail.transport.protocol>
<mail.smtp.starttls.enable>false</mail.smtp.starttls.enable>
<mail.smtp.auth>true</mail.smtp.auth>
<mail.smtp.ssl>true</mail.smtp.ssl>
<mail.debug>false</mail.debug>
<mail.smtp.quitwait>false</mail.smtp.quitwait>
</properties>
<mail.from.default>administrator@mydomain.com</mail.from.default>
<mail.from.name>Pentaho Administrator</mail.from.name>
<mail.userid>administrator@mydomain.com</mail.userid>
<mail.password>mypassword</mail.password>
</email-smtp>

When I hit "Test Email Configuration", it sits for ages then gives me;
Unable to complete email configuration test. Verify settings and try again.

I've tried setting mail.smtp.starttls.enable given that it's the only setting that I don't know, but itmakes no difference.

I know that the settings are correct because I use them in several other apps and in Outlook. They're also confirmed in the Rackspace documentation (https://support.rackspace.com/how-to...ange-settings/). Any ideas?