Outlook email keeps dropping and getting error saying unable to connect to Comcast server.

I have been battling issues for some time now with my email using Outlook on lap top which connection keeps dropping  with error pop up saying "connection to  Comcast server can not be established at this time - try again later.. "  I can access emails on Comcast web portal and I get them on my Iphone without issue. I have no other issues with internet connections on any other

internet traffic / web sites and it's only the Outlook email connection with Comcast now.  This has self corrected on occasion after a couple of days of downtime without any action on my part, but only to  resurface again after short time again preventing connection to Comcast email via Outlook.  I have gone into  Outlook file settings and did a repair prompt and after it scanned error  pop up saying " An encrypted connection to email server is not available" .  SO what's the problem with Comcast server not connecting to Outlook program ? I have have been using Outlook for over last 5 yrs with Comcast email and never had any problems until notably last 6-7 months.