[Gandalph]

This sounds very much like the behavior of the W32.klez virus. This is a worm virus that emails itself to everyone in the infected computers address book. It has a twist, however, in that it randomly picks an address from the address book to place in the "from" field so that the next recipient believes the email is coming from someone they know and opens it, thereby continueing the cycle. Someone in my circle got infected over a month ago and I still am getting infected emails. For this reason, it is imperitive to maintain a good antivirus program ( I personally recommend Norton AV 2002 as it scans both incoming and outgoing emails and does auto definition updates ).