You can receive notifications inside Yodiz tool or in email. You can configure these under your profile and notification settings.
To receive notifications when somebody tag you in comments or not. To do so you go to Notifications Settings from your profile and ensure that "Tag" is selected for Bugs, User stories and Tasks.
After making changes to your settings refresh page or go back to application.
Example is shown here.
Email notification settings
This screen shows email notification settings