How can I stop Mail.app (1.3.11) incessantly playing sounds?

I think you have to disable the "New mail sound" in the General section of Mail.app preferences.
Add a rule to play a sound if you want it for those messages not moved into some other folder.

Good idea. I'd forgetten there was a toggle for that.

One problem: I can't figure out how to create a rule that matches only e-mails that end up in "In".

Do I need to first add "stop processing" to both of the mailing list rules, then create a new one that stops processing if the e-mail is junk, and THEN create one that plays a sound for Inbox mail?

I guess the problem here is I'm not sure how the "hidden" junk e-mail processing works, or rather, WHEN it works. Does mail.app make a determination of junk-or-no-junk as soon as it receives the mail, then runs through the rules, and then if it doesn't match anything, moves it to "Junk" automatically? Anyone know how this stuff works, exactly? Does Apple have some actual documentation on it hidden away somewhere?

For posterity, and Google searchers, the answer to my last question is basically "yes". At least, that configuration seems to be working here. There's probably a better way. I now have, basically:

Rule 1: if match (whatever), move to mailbox (whatever), stop evaluating
Rule 2: same as rule 1, for a different mailing list
Rule 3: recreation of the "hidden" Junk rule -- if not in address book and message is Junk, move to Junk, stop evaluating -- A question remains: What if Mail.app thinks it's just, but they ARE in my address book? Does it still get the Junk icon, but not get moved? This would be very very ideal, so I can be alerted to this false positive.
Rule 4: recreation (again, sigh) of the default "new mail" alerting -- if (every message) play sound New Mail -- also a remaining question: so I stop evaluating on this one too? Does that even stop the hidden Junk rule from running? Would it stop other important things from running?

This all seems pretty ugly, but it works. Hopefully OS X 10.4's new Mail.app makes these rules a little less superfluous, a little more documented, and a little more flexible, eg, if (a or b) AND c ; then ..., which you can't do in Mail.app's rules in 10.3. (Or iTunes playlists. Very annoying. But I digress.)

-Jeremy M. Dolan

I had to do something very similar with Mail 2.0 in Tiger.
My rules are:
1) no junk past this point (a recreation of Mail's hidden Junk rule as seen in the Advanced prefs)
2) announce messages addressed to me by full name(an AppleScript that reads the sender & subject aloud)
3) match mailing list A -> move to box A
4) match mailing list B -> move to box B
5) etc
last) play sound for any messages that have escaped all the above filters

In this version of Mail.app at least, I determined empirically that the hidden Junk rule is run after all of the rules that I set. Hence the need for rule #1.

The rules only have "any condition" and "all conditions" - there is no more sophisticated logic available so you need to simulate it via several rules.

Yes, that also seems to be the case in Mail 1.3.11. Junk is checked BEFORE the first rule, but moved AFTER the last rule.

I'm still very curious to know if this means that, in my case, mailing list messages would still go to their correct folder even though they are marked as junk, and also for mail addressed to my full name, which should be excluded from the move. I'm tempted to send myself mail from another account and make it look spamy, but I'm scared I'll taint my filters.

I wish this stuff was a little more transparent.

PS: thanks for the help earlier, Hayne.

I wish this stuff was a little more transparent
Yes, that would be nice.
Perhaps turning on logging (see a recent forums posting about how to do this by using one of the AppleScripts that Apple supplies) might give more info?