Wow! Just got an e-mail from Ebill (ebill.co.nz) about an outage this coming weekend (24 April 2005), and they sent the e-mail with the users' e-mail addresses in the TO: field!
Not very safe practice. Granted first time it happened. Very strange. Don't like the idea of lots of other users knowing which e-mail address I have used to register on eBill.