Spam Flood

[#1]

The last three days has been a real pain for me.
Upto then, I would get about 40 emails per day marked as SPAM and put on the SPAM folder.  I would go into the folder and flag the NON SPAM emails and move them to my INBOX.  Normally 2 good emails flagged as SPAM per day.
I am now getting 400+ email per day and about 70% are going into SPAM and 30% into my INBOX.  It is now becoming a pain having to go through and move the emails into the correct folder.
Something has happened.

[#2]

With a sudden influx of spam, I'm not surprised that the spam filter is finding it difficult to be as accurate as it normally is.
Just a thought. Isn't there a fair chance that this sudden increase has nothing at all to do with PlusNet or Postini? When I started getting lots of spam about 5 or 6 years ago, I found out that one of our suppliers had put my e-mail address onto its list of distributors. Have those people who've suddenly got a lot of spam tried typing their e-mail address into a search engine, to see if any sites have it displayed?

[#3]

I tried a search of "******@******.force9.net" in five search engines and it found nothing.

[#4]

Quote from: Hobo

Though I still cannot see how Failed Delivery messages are getting marked as spam.

Sadly so many are now backscatter from spam attempts that spam logic may just treat it as spam. Either that or the message contains a portion of the original which trigger it.
Anyway, it may just be easier to mark them as spam rather than clutter up user's inboxes. Not technically right, but probably generates less complaints.
As for recent surges, they do go in waves (sometimes around holiday periods I believe), but also worth noting that ordb.org's DNS blacklist server started rejecting ALL mail recently. This shouldn't be a problem as ordb.org was effectively shut down a long time ago, however a lot of mail servers just have default configurations or have been neglected and are now rejecting a lot of mails. Hit me as my server was using it and I totally forgot! Oops.
Basically means, any mail server still using ordb.org as a DNS blacklist server will likely be rejecting all mail regardless, legitimate or not.