This tip is actually very simple, and works without the need to install any software or plugin. You can learn through your MSN Messenger which of your contact have blocked you, or removed from his list. To do this follow the steps below:
Click on the Tools -> Options
Select the Privacy tab
In this window you can see two lists. The left is your list of users visible, and the right is the list of blocked users.
To find out who blocked you, just click right over the spot you want to know. If the "Delete" option is available, then this contact you have deleted or blocked you on MSN it.
Easier than that, even just using Pidgin.
