Re: shocking
Distribution preferences explain the prevalence of Exim and Postfix: most people go with the default.
Currently still dealing with fallout of Hafnium on from that disaster waiting to happen that is Exchange, which requires its own web server to work. We've tried hardening it but have to keep ActiveSync, Outlook Anywhere and OWA active. We've got problems with Outlook for Mac dropping the tunnel because it doesn't have the Windows-specific proxy options to enforce basic authentication. I've just signed off on the bill for the extra support. And there is no redress for all this shoddiness from Microsoft.
Give me a flawed open source mail server over this shit any time.