I have received several emails from people I know and with legitimate messages from them. However the To: line has my real Mail address but with "Viagra®Official Site" added. When I start typing in my address in a new message, the V... stuff is automatically added to my real address. I checked my mail account and the address is correct there. There are no user accounts added to my MacPro in System Preferences. Is this a virus? Is it serious or just an annoyance? I'm reluctant to send any messages through this account because of infecting other computers, and/or being embarrassed.