Outlook Can No Longer Access Comcast Server

About 3 weeks ago, we had a Comcast outage in our area and after our internet access was restored, I have not been able to access the Comcast server to get my email via Outlook for Mac 2011.  I am able to get my Comcast email on my iphone and directly through the Comcast server.   Our internet access works fine, although it's slow.   I worked with Comcast technical support and with Microsoft and concluded that I needed to update to Office for Mac 365 and did so today.  I still cannot access my Comcast email via Outlook 365.  I receive the message "Unable to Sign-in.  Check your credentials and try again".  When I try adding my Comcast mail account through System Preferences/Internet Accounts, it just spins and is not able to add the account.    I have run anti-virus software and I updated to OS High Sierra.  None of that has helped.  Any ideas?