Last 14 days of Notifications can be found under the bell icon, next to project picker.
Notification sent for the following events:
Event
Recipient
Test Case sent to review
Reviewer
Test Case review finished (approve/reject)
Review Requester
Test Cycle assigned
Assignee
Test Execution Assigned in Cycle + Cycle set to Ready to Execute
Every Execution Assignee (Tester)
Cycle finished
Cycle Assignee
Comment Mention
@mentioned user
Notifications can be controlled by Project Administrators, from the project settings menu.
But they can be overwritten by users, by clicking the bell / cogs.
Comment section is available for every testing asset (Requirements, Test Cases, Test Cycles, Collections, Campaigns), in the Overview tab. Typing @ can mention other users.