Blocking a contact means that you will no longer be able to receive messages from that contact. This action can be reversed at any time by unblocking that same contact.
Blocking a contact
To block a contact, go to your Inbox and open your conversation with that contact. Then click on the Contact info icon on the top right corner of the conversation to open the Contact details window.
From the Contact details window, click the three dot Phone options menu and select Block Number.
To unblock a contact, follow the same path described above to the Phone options menu and select Unblock Number.
Blocking a contact for the whole organization
To block a contact for an entire organization, complete the following steps:
Log in to your organization's primary account.
Go to your Contacts page.
Select the checkbox next to the contact(s) that you would like to block.
Click the three-dot menu on the top right of the page for Batch actions.
Select Block number.
Any selected number(s) will now be blocked across your entire organization.