I received the virus emails forever with spoofed headers but not for dating. It started with one customer after he broke things off with one of his "investors" who has some IT knowledge (juicy gossip involving celebs! I'll have to kill ya to tell ya names! :o))

But the virus mails were intentional to destroy his Windows system and then filtered to anyone they associated with or assumed to be associated with. However, in each case, I found they were sending mails from the same remote static IP addressed public terminals via proxy. In one case, it was a cyber cafe in Africa, while the strangest was 2 blocks from the customer's address. In each case reported directly to the system admin via phone or email, the problem machine was immediately found by the IP address and the mails stopped, except for Verizon which just ignored the problem for about 30 days...

But for the emails soliciting girls, as you're in the United States, you should send those to your local attorney gen (askdoj@usdoj.gov) and cc the ftc (uce@ftc.gov). Some people don't understand that the same things you can't do offline, you can't do online (solicitation, drug trafficking, transmission of virus (malicious/threats) etc.). And you just never know who those girls are, or even if they're willling participants for the organization sending the mail.

But if you can view the raw source of the email, that should reveal an actual domain name so you can get whois or NameServer information to find the source of the problem.