The server cannot be contacted on port 995

I have looked around to find an answer but nothing I have found in the discussions or help pages worked or tackled this error for me. I get it intermittently. My provider checked that everything is ok with the server (its not one of the big ones like gmail etc but linked to my website provider who is a medium sized company).

Not sure how and when it started but only has happened over the last two or three days. I think it might have started around the last update I loaded but not sure. When it happens neither turning off the Mail nor the laptop helps (only sometimes it does). I'm reluctant to change any settings without properly knowing how and where because I don't want to make it worse.

Any help appreciated.