Obviously not, in 1990 it would have been published to Usenet group comp.sources, and all you would get would be source. OK, perhaps also a Makefile and a man page. (All packed in a .shar text file, a "shell archive" script that would run and unpack itself.)
Also, at least BSD used to come with /bin/mail, which would send mail from the command line as described. 'mail -s test joe@example.com < file.txt', if memory serves.
Considering what it does, the consequent benefits to it being open source, and that there are already open source tools to do this out there, it does not seem like an unfair criticism.
Having it open source is undoubtedly better, however one can simply ask for the source as often people do. Snark just leads to people not bothering at all.
As the old expression goes, "open source is more than just source code".
Honestly --and I'm not trying to be snarky here-- in this case, I'm not sure I understand how "not bothering at all" would actually be worse. Maybe I don't understand something about the value.
There are people making comments asking for help on OSX so they might have a different opinion than you, but beyond that we also have to consider other members seeing these kinds of comments may decide not to bother. So yes, you don't care about this project, but you might care about other projects that may never see the light of day as a consequence.
This is probably a dumb question, but how do I get this to work in OS X? Bash says it cannot execute binary file despite chmod +x /path/to/mailer - thanks.
In a similar vein but open source is ssmtp. It's a simple MTA that hands off the dirty work of sending e-mail to a real mailserver, and can be configured to use your existing SMTP server as a bounce point, or if you're running a personal server, your gmail account.
I'm not clear as to why anyone thought this tool was needed or was any more complex than a simple script. This functionality is built in to most platforms.