Again a spammer

Dear All,

I got yesterday and today several mails from "My List
<webmaster@vol.vnn.vn>", referring to http://www.duongquanganh.com.

It was again to my hn.vnn.vn address, which I do not publicize since
several years. Did anybody of you get also those mails (some "test mails",
then some real ones)?

If so: to which address? an "@hn.vnn.vn", "@fpt.vn", or ...?

I can't help, but think, that there is somewhere a leak, and that those
spammers get the addresses directly from the ISP, if the somebody in the
ISP is not the spammer himself. Can you help to find out?

Best regards,
Stefan