How to reprocess inbox?

How do I instruct spamsieve to reprocess my inbox? I have about 200+ new messages that did not get processed by spamsieve because I had to hurridly pack up to get on the train… and between forcing the laptop to sleep while mail was downloading on a very slow wifi connection I think spamsieve got a little confused.

Thanks

I think I found the answer, by clicking Message -> Apply Rules.

Correct.