1. You should immediately install a resident firewall if you don't have one. Either ZoneAlarm or SygatePersonal Firewall are free and will provide an additional layer of protection for your computer.
2. Has anyone OUTSIDE the membership of the YahooGroup received this Email from you? I presume we are talking about only ONE email and not multiple examples with different subjects/texts here, though your response about some do and some don't confuses me.
3. Are you 100 percent sure that any of these Emails supposedly sent by you show up in your Gmail sent box?
4. Can I assume you have run a thorough hard drive scan with your Anti-virus?
I am still not convinced that your computer (certainly it would not come from Gmail or this would be pandemic amongst its users) is the culprit. A firewall should prevent anything untoward leaving your computer, so future instances (even if your computer is a fault) will not occur.
I belong to many Yahoo groups, and in almost every instance where this has happened, it has been the result of someone else's computer stealing the sender address and using it to send malware to the group.
Edited by jgweed, 17 August 2005 - 04:17 PM.