Do you know if your emails reach your users' inbox? You may see clicks and opens, but were all your emails seen? SparkPost offers this certainty to developers for free or low cost. SparkPost sends 25% of the world's legitimate emails. They make solving email delivery as easy as making an API call.
Despite attempts to reinvent it, email is still one of the most popular ways to communicate across the internet. Developers have long been able to take advantage of Emails popularity using various libraries that support POP, SMTP and IMAP. This is fine when you have access to a publicly available web server, but for small and hobby developers this can be an unacceptable cost.