In late February 2009, I suddenly started getting about 50 spam comments per day on this blog. They all had similar content and were coming from only 2 or 3 sources. The blog is running on a GoDaddy-hosted site and is a manually installed configuration of WordPress 2.7.1 (rather than the WordPress installation provided by GoDaddy).
So, after first manually deleting all spam, I activated the famous (but oddly named) Akismet spam filter. It is by Matt Mullenweg, one of the WordPress founders. It seems to do the job. And it generates nice-looking statistics of the amount of spam received per day.
Puzzle: bug or feature?
The statistics show indeed roughly 50 new spam comments per day. But these do not show up in the Spam category under comments. Akismet has a procedure to check the spam filter by logging out and posting a comment to your own site under user name “viagra-test-123”. That does creating a posting which is classified under Spam and which can be reviewed.
Three friends using WordPress did not have a real solution/explanation. Searching the Akismet.com site also didn’t help. Wild guess (I have no evidence): Akismet has 2 levels of spam. Span that is absolutely certain to be spam, and is not saved and thus not reviewable. And normal spam (including spam generated by viagra-test-123) that is saved for 15 days and is reviewable by the user.
Note that this is not a big deal assuming that Akismet is accurate enough to avoid false positives. But I need to see the spam to judge…
Update (10 March 09)
After a few days, the filter started to behave. First spam comments started showing up in a reviewable location. A few days later, it started treating non-spam comments (“Ham”) correctly. The amount of incoming spam also dropped by an oder of magnitude. No good explanation yet.