It’s always the simple things that reach out and grab me. Here’s shush, which I almost skipped over because ideally, it needs some sort of local e-mail subsystem to do its job correctly.
Yes, I know that’s really only half working there. I was surprised I got that far, really.
If I understand it properly, it should ideally run command, then wrap up the output and mail it off to the responsible parties.
The home page says it’s meant to run alongside cron, meaning you could ask shush to send the output from regular cron tasks to an e-mail address. And from there, the options are limitless.
It’s a very simple idea, but not one that I usually see as a free-standing application.
I don’t have many tips for setting it up, as you can tell by my botched attempt to show it in action. 😳 On the other hand, the man page for shush has a rather complex example that you can break down into pieces, and probably get something better.
shush is in Debian but not in Arch/AUR, which surprises me. I am sure someone will tackle that omission in quick time though. 😉
Inconsolation 
I can not compile the program, but your problem is that you dont have a local sendmail process. Maybe you can use SHUSH_SENDMAIL environmental variable to redirect shush to a fake sendmail, something like this line from your shell (not tested):
SHUSH_SENDMAIL=”cat – >> /tmp/output.log” ./shush -m -H -c /home/kmandla/.shush/ free
and see /tmp/output.log contents ?