You seem to have installed the sponsor program by mistake: you selected "I ACCEPT, install the sponsor" in the installation program - most likely accidentally, without reading correctly. You can uninstall it easily by reading and following the instructions as given in
http://shoutbox.menthix.net/showthread.php?tid=21598. If you follow those instructions exactly as given, you will have no more ads left, and the toolbar will be gone.
Remember that you should close as much open programs as possible, and you have to close all open browser windows in order for this to work.
Also, Messenger Plus! does not send viruses. In fact, it doesn't send emails at all. This problem is not related to Messenger Plus!.
If you see warnings while using the software: these virus warnings and/or spyware warnings some (antivirus) programs (mainly AVG) give, are not true; these are false warnings. You can read more about these false warnings at
http://shoutbox.menthix.net/showthread.php?tid=16516.
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