I've received three e-mails telling me that messages I'd tried to send had failed, except that I didn't send these messages. The three e-mails were to contacts in my contacts list but were spam for a Canadien pharmaceutical company. I use Google mail, through Mail on OSX, and they suspended my account temporarily for doing this. Have I got some sort of Trojan on my beloved MacBook Pro? I didn't think there were any in existence for OSX. Any advice please.