There is an Ignore feature in Outlook that allows you to move all the current (and future) emails in a particular thread or conversation into the Delete folder. To turn that on for an email thread, highlight one of the emails in the thread and then click the Ignore option in the Ribbon Bar:
Outlook will find all the emails in that thread and move them to the Deleted folder:
But what if you decide later that the email thread was relevant, and you really do need to follow what’s being said? You can reverse the Ignore by going into your Deleted folder, right-clicking on one of the emails in the thread, and selecting the Ignore option:
That brings up the following dialog box:
Click on Stop Ignoring Conversation. All the emails in that thread go back into the Inbox, and all new emails in the thread will show up there.
I highly recommend using this feature if you get caught up in a Reply All email storm. It’s also a great way to filter out a long-running email thread where you were initially cc’d but you really don’t need (or want!) to be part of it.