I got the following reject this morning: <book...@example.com>: host mail.example.com[1.2.3.4] said: 550 Dynamic Style reverse DNS IP=[212.25.14.40].Rejected by MagicSpam 1.0.4-9.1 (http://www.magicspam.com/).
Do a reverse look up of 212.25.14.40, and you'll see that it's perfectly alright. /Per Jessen, Zürich