[b112]

The thing is, it's not "another tool", but instead "a tool deployed in at least hundreds of millions of *nix servers, which is rigidly compliant with SMTP RFCs, etc, etc".

If you want to debug issues with sending mail from code, then ensuring you have something that will scream if you "do it wrong" is a big bonus. And having something tested for 20+ years with rigid adherence to RFCs, deployed more widely than any other *nix MTA, is probably a good thing too.

In terms of "essay", I know it looks big on your phone screen (I presume), but a few paragraphs of background info is hardly that.