This is SBS 2011. Our ISP is Shaw Cable.
We have a weird problem as below -
We cannot open the URL http://webmail.shaw.ca
in a browser, and we cannot ping webmail.shaw.ca
We cannot ping all of our ISP pop3 servers, such as shawmail.vc.shawcable.net
If we run "Connect to Internet" wizard from SBS Console, the above problems will all be gone. But, the problems will come back again in a day or two, so we will have to run the wizard again and again.
We have no problem with our own domain emails (@mycompany.com) and we have no problem with browsing any other web sites.
This is a DNS issue that is only related to our ISP name resolving. But I do not know where to start to troubleshoot.