We have a network running off a SBS11 server and Sophos anti-virus. Until yesterday we could view all web sites ok. Without any apparent changes to the system, this morning we can view any web site as long as it does not end with ".biz" (.com, .org, .com.au etc are ok).
I have not made any changes to the server. We cannot view the .biz web sites on any of the work stations, the server itself or a Tablet that connects with wifi.
It affects email also.
It is as though the server has suddenly decided to filter out anything with .biz extension.
If I send an email from a .biz site to this site it is ok, if I send and email back or reply to the email from .biz domain - it never arrives there.
Chrome browser reports web site not found. IE reports problem with DNS.