What I try to achieve with Rules:
After saving a new comment, this comment has to be sent only to those users who've checked a corresponding boolean box on their profile page.
Drupal Answers is a question and answer site for Drupal developers and administrators. It only takes a minute to sign up.Sign up to join this community
Assuming your question is about D7, there are basically 2 ways (options) to answer your question, as further detailed below.
You could create a view (using the Views module) of those users that you want to send an eMail to.
For more details, have a look at the tutorial "How to process the results of a VBO enabled view via Rules?".
... provides two types of elements in Rules, configured with a "Rules" view display:
Views loop: A views loop is similar to a regular Rules loop, but allows looping over rows of view results.
Collect view result rows (action): This action collects each variable in all view result rows into list variables for use in Rules.
Tip: When selecting the data type for variables in the view, if the field is an entity identifier (e.g. Node ID), you can set the data type to the entity type (i.e. Node) to directly use the variable in Rules as an entity!
After you enable the Views Rules module, you can use Views to create a view of those users that you want to send an eMail to. Add of view of display type
Rules (important, that's the key to make it work!). Here is how you can add such display:
Next configure the row variables, by using the link that says "edit field info", as shown here:
You probably want to use one or more of the variables similar to those that are shown in this screenprint:
Create a rule that looks like so:
Add view loopto add a Views loop, and select the "Rules" display created in the previous step.