The easy answer is to use an smtp server; many languages have stable packages to implement that. You can also use postfix with procmail or exim - leave the smtp

The easy answer is to use an smtp server; many languages have stable packages to implement that. You can also use postfix with procmail or exim - leave the smtp stuff to tried and true packages, and have your code receive messages either via maildir or direct scripting. The long answer is: first make sure you don't have a blacklisted IP; ask your cloud provider for permission to enable an MTA (mail transfer agent) and have fun seeing 99% of your email traffic being either brute force auth attempts or spam delivery attempts.