Mail, and it's Rules

[John Pariseau]

I recently started using Mail.app's rules, and was wondering if too 
many rules can cause problems with mail. I have been (slowly) adding 
certain words and phrases to 3 rules, to filter out most of the junk 
email I get. I use Mail's "Junk Mail" feature, but since it has 
incorrectly tagged messages (only a few times), I manually delete 
messages that get through my rules.

Will too many rules and conditions cause slowdowns in getting email? 
And if so, how many is "too many"?

Thanks!