Also wenn der Kommentar nicht gefressen wird, dann weiß ich auch nicht …

Owens spam action
You can (all optional):
* Delete every comment except those written by logged-in WP users of a level you specify.
* Delete comments based on IP (plain text or regex)
* Delete comments based on content, email, or URL (plain text or regex)
* Send comments to moderation that fail to include the special OSA form fields (auto-generated hash unique for each comment).
* Send comments to moderation for incorrect referer.
* Send comments to moderation for including HTML entities (a common spammer tactic for eluding text filters).
* Send comments to moderation that were sent through a labeled proxy (when HTTP_VIA header is included).
* Send comments to moderation that were submitted for posts older than a number of days you specify.
* Close comments for old posts entirely based on your setting.
* Set a maximum time between receiving the comment form and submitting it.
* Set a minimum time before submitting a comment.
* Delete comments that fail any OSA check.
* Delete comments that fail any Discussion tab checks.
* Append diagnostic info (server variables and form elements) to moderated comment email.
* Keep a count of the number of deleted comments. Mine is currently at 897.

Bad Behavior
Bad Behavior was designed and built by watching actual spambots which harvested email addresses, posted comment spam, and used fake referrers. By logging their entire HTTP requests and comparing them to HTTP requests of legitimate users, it is possible to detect most spambots. Bad Behavior blocks spambots with a 412 error. It also has three configurable User-Agent lists for spambots and other malicious bots which actually identify themselves. Bad Behavior can use string matching or regular expression matching against a User-Agent. Bad Behavior intends to target any malicious software directed at a Web site, whether it be a spambot, ill-designed search engine bot, or system crackers. In that spirit, it is not limited to WordPress users; a generic interface has been provided whereby it can be integrated into virtually any PHP-based software.