Allen, I don't think your ISP's going to care, unless someone's attacks are disrupting ISP services themselves (pelt another user to death, they won't care, but bring their website/email server down, and they'll be breathing down your neck!) :)
If you post the relevant details of your attack, I...
Can you post the entire text of the message? There's more info in there than just the IP, such as the protocol and port, which tells you what attack was used (if it was an attack in the first place), and so forth.
You can find the info in NIS's activity log.
KJP