FIXED! After months of asking about the improper email paragraph spacing and getting no response by phone, email and on this Forum, I FINALLY got ahold of someone with Comcast (through Facebook, of all places!) who understood what I was talking about and wanted to help. It took a couple of weeks of back-and-forth, but she set up a meeting, discussed it, and was successful in getting it changed. I have been doing test emails for the last week, and the problem has finally been fixed. SINGLE SPACES ARE NOW SINGLE SPACES AND DOUBLE SPACES ARE NOW DOUBLE SPACES.
A simple and silly problem that was started with a change to the email system over a year ago, and a problem that no other email provider (Gmail, Yahoo, Hotmail or others have). I've seen numerous complaints by others about it on this forum, with no result, so it's a relief to have gotten some assistance.
At some point, departments within Comcast need to start communicating with one another instead of all heading off in their own directions and, worse, letting problems continue as long as this one. I hope this reaches others who have been trying to get it fixed. And my thanks to "Chris," the person with Comcast who took the initiative on this and got results!