Blocked from sending messages on facebook?

[Sasha]

I don't understand why... I was trying to send a message to various friends, one of which does not have facebook. So I was trying to send the thread to 8 facebook users and another user through email. However, it said that the email was invalid, so I tried using a different email and clicking send various times to see if it would work. (most times it said "transport error).. Then facebook said I was blocked from sending messages because I was engaging in potentially abusive behavior or spamming? I checked my sent messages box to see if the message had, in fact, been sent, and it was not..
How can facebook ban me on the grounds of a message that was never sent?
How long will this last?