Today, Robert reported that he is seeing a higher then normal spam volume. We do get notes like this rather regularly. Usually, its just a matter of "your turn coming up" in the global spam game. Here a few URLs I use to check on the global spam volume:

Spamcop http://spamcop.net/spamgraph.shtml?spamstats

Messagelabs: http://www.messagelabs.com/intelligence.asp

Postini: http://www.postini.com/stats