Unwanted messages from contacts on Yahoo Messenger create annoying pop-ups that you have to close; the messages can even continue when you’re offline, greeting you as soon as you sign in. Blocking the contact gets rid of the problem, but may offend the person being blocked. Luckily, Yahoo Messenger doesn’t notify the blocked person of the block at any point in the process or after it’s complete. Writer Bio

When You Block Someone on Yahoo Messenger  Do They Get Notified When They Try to Send You a Message  - 17