I’m really enjoying eM Client, as is my wife. We’re both sick of both Thunderbird and Outlook: Thunderbird because of calendar and contact sync issues, Outlook because of IMAP issues generally.
eM Client seems to work very well in all areas. Support issues have been fixed quickly. My (many!) feature suggestions have been acknowledged promptly too.
I’m baffled that there isn’t a free, open source mail/calendar/contact app that works on Windows. Good luck to eM Client while it has the playing field to itself! The licenses I have bought have been money well spent, I believe, and I say that as a supporter of free and open source software in commodity functional areas such as this.
My PC just crashed and I noticed eM Client conducting a discrete data integrity check when it recovered. It’s good engineering like this, with a competent UI, that makes eM Client such a pleasure.