Ok. Just checked my sky hub log for the time I got the email. This is what it says. I have blocked out the ip address below
Aug 21 21:16:22 syslog: Send out NTP request to ntp1.isp.sky.com
Aug 21 21:16:22 syslog: Received NTP Sync Reply from ntp1.isp.sky.com
Aug 21 21:16:22 syslog: System time is up to date
Aug 21 21:24:07 syslog: Lease renewed 3600 ip Xxxxxxxx