>>7
Anyway, you should be clever about it, not just send a blank e-mail.
For instance, if you know they are a fan of some obscure freeware program, use the service e-mail address associated with it and write a message like "Due to negligence/a hacker on steroids, a security loophole/virus was accidentally contained within the last release! We're sending this security fix that will reinstall the program and fix the bug/remove the virus. Thank you for your continued support." Or something like that (be more subtle, obviously; say the website was hacked and they are in the process of setting up a new one or something).
Or send it from the email of another of their friends, and say it's a mod for some game they like, etc. It's a good idea to have the executable do something IN ADDITION to setting up the keylogger, so they don't get as suspicious as quickly.