Why do anything that makes sense? All I can say about the PHP maintainers' decision process without swearing is that it bewilders me.

Last time I tried configuring a Linux-hosted PHP to do SMTP on localhost:25 instead of shelling out to call sendmail, I found that only Windows builds even have that functionality compiled in. You can apply the same configuration options on a stock Linux build, and they won't cause errors, but they won't do anything, either. Maybe that's changed recently, but it would have to have been very recently, because I ran into this (for the umpteenth time) just a few months ago, while reworking my team's dev environment to allow for examining sent mail without requiring heroism.

I'm not a PHP hater, exactly. I don't like the language at all, but I understand it well and have made a very good living based partly on that knowledge. But the mail story in PHP has never not been a dumpster fire.

There are hundreds of ready made libraries which help you easily talk to SMTP without invoking a shell cmd. You also have the option to use sock functions (fsockopen) and write your connection wrapper. These are not windows-only features.

Of course. The part I still can't get my head around is where the language feature that'd relieve me of the need to vet a library, or worse write socket code by hand like some kind of barbarian, isn't compiled in for non-Windows platforms, because reasons.

¯\_(ツ)_/¯ PHP. This is one of the insane decisions made in PHP4 that stays there because it's always been there.