There are 2 ways of updating your Server:
1. Go to your server-manager's "Software installer" panel. There should then be a notice that there are updates available. Simply press the button to apply the updates. The panel will then lead you through the installation.
2. Go to your server console (physical console with keyboard and monitor or SSH with putty e.g.). Issue yum update
and follow the instructions.
About the other email: Would guess that's just noise, as it says there is a missing temp directory, but not sure if that's something to worry about.
Merry Xmas