Outlook not working - cannot send/receive

We had the same thing on Jan 21 at 4:30 we lost our email access on the office computers and on our cell phones.  The next morning I got an email saying Comcast had upgraded to Outlook 2010.  We finally got our cell phones to work but still no office computers.  We have been operating Office 2013 for 2 years with no problems.  I called Comcast, they say not their issue and for me to contact Microsoft.  I believe it is a Comcast issue and it is related to the server name.  They have a list of dns names for domains which has changed. I have tried everyone of them and nothing works. My computer says Outlook is offline. I have gone to outlook to troubleshoot offline, no remedy.  This angers me that there is no support from COMCAST. They are the worst service out there for a business to use. Anyone having the same issue?