How do you clean-up and fix a security break to your email account?

Someone breached my account while it was closed and used it to send malicious emails to people in my address book which linked them to a site in Canada? How can I fix this?|||change your password. If that alone doesnt cut it, you most likely are using a computer with a keylogger on it. Library or school computer. If neither and you simply use your home PC, someone close to you has a keylogger on your PC.