How do I clear a conversation from my inbox or delete a message?
In Conversations, each row in the list is a contact, not a single message. To clear a row from your list, mark it as done with the checkbox at the top right, or snooze it. Done and snoozed conversations leave the list, and you can use a filter to exclude snoozed ones.
Do not delete the conversation row to clear it, because that deletes the contact.
An individual message cannot be deleted once it is in the conversation. Use done or snooze instead.
To tidy the list, click the filter icon at the top right and minimize automated messages, so you only see the manual messages.
To see every thread with a contact in one place, such as separate email threads and an SMS conversation, open the right side menu of the contact and scroll down.