To block unwanted contacts from messaging you on Voxer perform the following steps:
From your "Contacts" tab > locate friend > press and hold down on their profile picture > select "Block and delete".
Note: Selecting "Block" means that you will no longer receive text / audio / image messages from that person. The person who was blocked will not be not notified that they have been blocked. Tapping "Block and Delete" blocks and deletes a person. Delete means that that person will not show up in your friends list anymore.
* For enhanced privacy within the app, please also see our how-to page about Privacy Mode.