We have a SBS 2011 Standard server that I setup about 2 years ago. We have Exchange running on it and everything has been working fine until yesterday. Users with Outlook 2010 are now getting certificate errors when using Outlook. It pops up a warning about the the certificate being expired and they have to click 'continue' or 'yes' to get through. Everything appears to work fine in Outlook other than the warning message. I never bought a certificate for the server as all of the users have desktop PC's and they never really do anything from outside the office. Is this something from Outlook Anywhere that is causing the security pop-up? Do I have to purchase a SSL certificate to get rid of the warning or can I reissue the built-in server certificate.
Thanks for any advice.