Send email based on post tags?

Hi, here is my use case; please let me know if this is doable, or if customizations would need to be made:

I would like to add my users / subscribers and have them follow certain tags.

Then, when I create a new post that contains the tag(s) they are following, they should get an email.

Here’s the catch: If someone is subscribed to multiple relevant tags, they should only get one email about that post, not multiple emails.

PS – My specific use case is to build a task management system so my list of contractors can get notified of tasks that related to their skills. So I would tag posts with skills (eg, CSS, HTML, PHP, etc) and then when I publish an email would go out to the right people.

Thanks for your support! 🙂