You can block a contact through Gmail's chat feature or through Hangouts. In any case, you can unblock the contacts in Gmail using the unblock option next to contacts or within the chat window, but the changes are only in Gmail. If you want to unblock contacts for Gmail, Hangouts, and other Google products together, you must unblock it from the Blocking People list of Hangouts . Unblocking in Gmail Blocked contacts are not visible in Gmail's chat list, so to find a contact, enter the person's name or Google ID in the search field of the chat panel. Move your mouse pointer over the contact and then click on the "block" that should be checked currently. Doing so contacts off in Gmail immediately and allows to reproduce contacts in the chat list. If you already have a contact open in the chat window, you can also click on the "More" menu of the window and then select "Unblock" Unlock contacts within a hangout Click the triang...