Spam rates are way up.
Spam took a big hit, and was cut tremendously in November, but now, the spammers are back with a vengeance! Have a look at the recovery stats. That is massive growth and it's now worse than it was.
I've personally seen this with my optusnet account spam rates going from 40 over a running 7 days, to 136 as of today.
Here's a sample of my recent spam. Nice.
I use the Spamato plugin for Thunderbird. It's working pretty well.
[update 13/6 - 166 spam in the last 7 days]
[update 16/6 - 184 spam in the last 7 days]
[update 20/6 - 123 spam in the last 7 days - seems to be abating!]
[update 24/6 - 54 spam in the last 7 days - thank the gods.]