As someone who's ran their own mail server and even wrote some super basic list management software years ago, e-mail is no picnic, especially nowadays. You can integrate with some 3rd party SMTP providers like AWS SES, Postmark, etc. but you still need to do a bunch of work to make it happen.
One other common way to do this is most providers can ping your website's RSS feed periodically for new content. They handle all the legwork, cron jobs, etc. behind the scenes. You can usually spit out custom fields (like perhaps a header image, etc.) and then craft the e-mail based on those. Active Campaign and MailChimp are good examples of providers that handle this.
Setting up an RSS Feed in Craft is also super straightforward—no programming, plugins, or API necessary. You just create a new template in Craft, name it with an
.rss extension and let Craft handle it like normal.
And the best thing is, if if you move providers, you can just unplug from one and setup the feed in another.