Opt-out / unsubscribe shortcode available?

Noob here, sorry.

I’m trying to replace the “email new posts to subscribers” feature from Jetpack. I found another plugin (“email subscribers and newsletters”) and fought with it to build an email list using existing subscriber data (ultimately used myphpadmin to dump WP_USERS, then import as CSV). However, that plugin doesn’t seem to allow me to send a single opt-in message: I can only send messages to the entire community and ask them to opt-out (that invites SPAM complaints, and that’s not straightforward either). Also the English is poor, and the diagnostics sometimes incomprehensible. Anyway…

Found this plugin, and I have to say it’s a lot easier to understand and use – but is there some ability for a user to remove themselves from a notification list?

Failing that, if anybody can recommend a better approach (than Jetpack) to this problem?