[bastawhiz]

There's no universe where I'd trust that there's already some binary on the system to send mail for me, but I definitely wouldn't roll my own. For any reasonable language, there's a multitude of SMTP client libraries available if there's not already one in the stdlib.

[erhaetherth]

I'd give up instantly and outsource it to a SaaS. I'm no expert on email but I know enough to know it's a PITA and managing delivery is a thing, and you have to make sure your DNS is configured right out the receiver will just reject it, there's reputations to consider, you probably want to throttle how fast you send it.. ugh.

[kazinator]

They are relying on a cron program being there, so ...

You can require it and it gets provisioned.