Chessdotcom has an interesting article by FirebrandX, a player who in real life is Wolff Morrow, an ICCF IM and the 19th US Correspondence Champion. Morrow is a graphic artist and computer technician. You are probably familiar with some of his work because he has designed roughly 100 chess book covers for Gambit Publications.
Morrow became interested in chess when he was 23 years old in 1997. Prior to that he was an avid video game player, having won a couple tournaments and set a few world records. He eventually began playing in OTB chess tournaments in his thirties, but found the costs, time, and travel difficult to deal with and when, at the age of 35, he defeated a master, he decided he had done as much as he could in OTB chess. In 2007 he happened to see a "rest of the world" match versus Gert Jan Timmerman which piqued his interest in correspondence chess and in 2008 he joined ICCF.
In the article Morrow explains modern CC as played on the ICCF and attempts to refute GM Nigel Short's comment, "Correspondence chess has become just pushing buttons on a machine." Morrow comments, “Some will even react very negatively to the accomplishments of earned ICCF title holders...citing a lack of over-the-board mastery of many ICCF players and believing that the level of human interaction in engine-assisted correspondence chess must be minimal as a result. The reality is nothing could be further from the truth in strongly-rated ICCF games.” In the article Morrow explains how a low-rated OTB player can actually succeed in playing at a decent level in CC. What skills are required? Morrow explains them.
One interesting observation was that once your opponent becomes skilled enough in opening theory to reach a playable middlegame, your chances of finding a win become extremely remote and the ICCF World Champion Leonardo Ljubicic's winning 4 games in the event was actually an incredibly impressive accomplishment. I hate to admit it, but, yes. Yes, winning four games in a modern correspondence tournament is an incredible accomplishment. It's kind of sad, really.