Hotmail Corporation v Van Money Pie Inc

• Hotmail Corporation operated the free web-based email service hotmail.com (at the time, one of the largest email providers)
• The defendants sent millions of unsolicited commercial emails (spam) advertising adult websites and get-rich-quick schemes
• The spam emails forged "hotmail.com" addresses in the "From" and "Reply-To" headers
• Recipients who clicked "Reply" or reported abuse sent their responses to Hotmail's servers, overwhelming resources
• Hotmail's reputation was tarnished by association with pornographic and fraudulent content
• Hotmail's terms of service explicitly prohibited spam

1. Whether forging a service provider's domain in spam email headers constitutes trademark infringement
2. Whether the resulting server overload from misdirected replies constitutes trespass to chattels
3. Whether an ISP can obtain injunctive relief against spammers

• Using "hotmail.com" in forged headers creates a false association with Hotmail, constituting trademark infringement and unfair competition under the Lanham Act
• The resulting flood of bounce-backs and complaints to Hotmail's servers constitutes trespass to chattels (interference with use of computer resources)
• Preliminary injunction granted restraining defendants from using any Hotmail domain in email headers or communications
• The case established that spam with forged headers is actionable under multiple legal theories

Forging a third party's domain name in email headers is a misuse of their trademark, creating false endorsement or association. The resulting server burden from misdirected traffic constitutes a tangible interference with the plaintiff's property (trespass to chattels in the digital context). ISPs have standing to protect both their mark and their infrastructure.