The purpose of those mails are to fool any filter and get to you. Therefore they use bogus addresses that live for a day or two. Making it harder to block. Sometimes it takes to much time to filter a message that it isn't worth it. Many companies uses a service to distribute there legitimate mail. Esp ads or mass-mails. Then coming from another source. We can think what we want about it, but it hinder the returns to flood their own email system. To write filters for each of those addresses is no way to go. UNLESS you can find some recurring phrase. You can teach your spamfilter, what to mark as spam. You can set up a new address-book with NOT-ACCEPTED addresses and filter for any mail that has any of those addresses to be marked as spam and moved