I’ve used Outlook a lot. It has a lot going for it. It is widely used in companies, as far as I can tell. It has the ability to create folders and setup rules to sort incoming mail into those folders. It uses Word as it’s editing engine, so it has nice spell check, grammar check, some auto correction of spacing and capitalization, who knows what else that I take for granted. I like the idea that it has VBA available, although I’ve not used it for much (yet). Dragon Naturally Speaking, which I’ve been trying to like and learn to use for 15 or 20 years, works much better with it, than with other similar programs. The spam filtering is not too powerful, but with Popfile set up as a proxy, to sort incoming mail, that problem is pretty well under control.
On the negative side, it is getting long in the tooth, and a lot of the configuration is difficult to locate and understand. It is a closed system, which is easy to get things into, but not so easy to get them out.
I switched to FOSSAMAIL a few years ago. It is built from the Thunderbird source code. Unfortunately, FOSSAMAIL is no longer being supported. I’m still using it, but thinking I should switch back to Outlook or some other supported program. I like it because it is 64 bit and has built in spam filtering which works even better than Popfile. It finds spam that Popfile misses. I use its findings to correct Popfile’s understanding. It has folders and a pretty good rule processing mechanism.
I recently found out that Thunderbird is now available in 64 bit version as well. I’ve installed it, but have not made time to see how I like it. That’s on the really long list of things to explore.
I’ve tried many other clients on my Android phones and tablets, but have not found any that I like very much.
What clients to you use? and Why?