There are two ways to follow tags without specific search words, one through SE, and one through a third party service:
- You can click "subscribe" on a given tag (you'll see it in a dropdown when you hover over a tag), which will send all new [tag] questions to the email you used to register your SE account.
- You can copy the RSS feed address from the tag dropdown, and put it into a service like IFTTT, and create a recipe to send all new questions to your email.
I have done both for tags that interest me on various SE sites, even going so far as to send some new questions to my phone as a text message from my Gmail account, so that I can read the new questions without having to go online for it.
To get an email for every new [tag] item that matches a specific search word, you can create an IFTTT recipe that will do that for you, in under a minute. Select the "Feeds" channel, create the action "new feed item matches," enter your search term and feed (from the tag dropdown), then select the email option for the action, and you have a functional recipe!
(It sounds a lot more complicated than it really is, I promise ;-)
For your search words, you can use this recipe. Enjoy!