If you have a plenty free time and enjoy analysis you will enjoy correspondence chess. And if you want to play at the master level, in addition to being a strong player, you’ll need a strong engine and a knowledge of the finer points of how to analyze with one. Just like in OTB chess, nobody reaches correspondence master without a good understanding of the game because to reach master, you have to be able to shoulder your way past all the other engine users. Please, if you are going to use an engine, then be fair and play on a site that allows them! If your playing strength is good enough and you are patient enough you can get a master title. It would help if you were like the Norwegian Frank Hovde who in the 1980s chose to live alone so he could do proper analysis without interference or outside distractions but that’s not an option for most of us.
Most OTB players and even some CC players don’t understand how chess, especially correspondence chess, can survive in an era where engines are in such heavy use. For now the fact is that CC at the top level is a demonstration of the limitations of chess engines.
But if you want to play CC, you should be aware of the conditions you will face. As a CC player you will have a lot of time for analysis and when you throw a strong engine into the mix, CC as it is played today even at lower levels, is at a really high level. Of course I’m talking about international play on sites where there are no rules against engine use. On server sites that forbid their play none of this applies...at least below the master level.
It is extremely hard to beat anybody and their engine. To do so you will have to know when your engine is giving you misleading evaluations and that is very difficult unless you are of at least IM strength. The best most of us can hope for is that we are more patient than our opponents and are willing to let our engines run longer than they do plus by patiently double checking the engine analysis for missed opportunities, we get lucky once in awhile and find a flaw...it can happen.
Programs don’t play perfect chess so a lot of work is still required. Once player who is both an OTB and CC master once pointed out that before you start going deep into the analysis of a position, you must make sure you look at a broad selection of moves because sometimes you will find variations that an engine may have discarded in its trimming process. This was the way he discovered many good ideas. Of course being a 2300+ OTB master gave him the edge over most people when it came to rooting out those ideas!
It’s true that a deep understanding of chess and strong OTB strength is required to be successful when engines are in use and therefore, climbing to the top levels will remain beyond the reach of most players. But isn’t the same thing true of OTB chess? Nevertheless, we all keep trying.
If you play CC at the lower levels, don’t worry about engine use...have fun. If you are going to be playing at a level where you do run into engine users you will need to make a decision of what to do about it. I elected to confine my play to sites that allow engine use and educate myself in the fine art of engine analysis. The result has been that my engine based analytical skills have improved leading to better results. Also as a result, maybe my chess has gotten better, too. The main goal remains the same as when playing at the lower levels...have fun. Hopefully as a bonus there will also be some improvement.