When a contact is blocked, all of their conversations are marked as "spam" rather than being categorized as "open," "automated," or "closed." While blocked contacts can still send messages, you won't receive notifications, and their messages will no longer appear in your inbox—unless you specifically search for their phone number.
If you decide to unblock a contact later, their past messages (sent while they were blocked) will still be available and viewable.
To block a contact, follow these instructions:
Navigate to the Contacts section to view and manage your contact list. Use the search bar or scroll through the list to locate the contact you wish to Block/Un-block.
Click on the contact’s name to open their details in the right-side panel.
Click the three dots next to the contact’s name and click on Block/Un-block Contact, and confirm by clicking on Yes, Block/Yes, Un-block.