If your inbox is cluttered with conversations or email threads you don't need to be part of, use Ignore to delete the emails. And any future emails on the subject will automatically be deleted.
Select the conversation or an email in the thread.
Select the arrow by Delete > Ignore.
If prompted, confirm by selecting Ignore Conversation.
Note: The Ignore Conversation command in step 3 appears in the Ignore Conversation dialog box. This dialog box doesn’t appear if you previously selected the Don’t show this message again check box.