With Hello Talent you can send bulk emails. To do so click the advanced search button at the top of the page.
You'll then be presented with a list of all candidates in your pool. You can use the search function to filter for specific profiles. Within the list of profiles hover your mouse over them in order to see a check box appear next to each candidate. Check as many boxes as you need to select the candidates who will receive the bulk email.
Once you've selected at least one candidate the "send email" button will appear. From here you can compose your email, use a template if necessary, and then send it.
Note: If you select candidates who don't have an email address Hello Talent will not include them in the bulk email that is sent.