Apple Discussions is filled with complaints about how upgrading to Mac OS X 10.5.3 Leopard kills the "Incoming Mail Sound." Seemingly, not only those upgrading to the latest version of the OS are having this issue. Also, the problem is tied to more e-email protocols than just the POP, as the thread reveals.

Thread starter Real Max says "Incoming mail sound STILL NOT fixed" and asks for an Apple-script free solution.

"SAME issue here," another clearly upset user writes. "Have called Apple support twice about this (I have brand new white MacBook)... They say they have heard of NO other reports of this problem. Hmmmmm... I commented to the technician that there were numerous documentations of said 'incoming mail alert sound' problems referenced right here in this forum. That comment was completely ignored. Therefore, I have come to the conclusion that if Apple says there is no issue, then (according to them) there is nothing to fix and all of us who happen to have this nonexistent problem are just nuts," the disappointed MacBook owner ends his post.

At a first glance, it seems only users with a POP mail account are having the issue. That's false, as MacTimelord reveals in the post I'm about to paste for you right below. Also, the problem isn't tied to the latest maintenance update for Leopard, as previously thought. Mac users running earlier versions of Leopard (below 10.5.3) are also having trouble with the incoming mail sound:

"Several weeks ago we took delivery of a new MacBook (with OSX 10.5.2), the 'New Mail Sound' has never worked on this computer. There are no third party applications installed. The email account setup on the MacBook uses a .Mac address." He goes on to explain how he created several new user accounts using a .Mac address for the Mail setup. "Still no 'New Mail Sound'," he claims.

After trashing the preferences, he got on the phone with Apple Care, trashed and reinstalled the Mail application, trashed caches too, but still "no New Mail Sound." Later on, the guy decided to use another email address and setup a POP account, which proves the issue isn't tied to this e-mail protocol and, "instead of setting up a new user with a .Mac address" he went with another e-mail address. "The 'New Mail Sound' played!!!'," the guy happily told his fellow Discussion-ers. "But it only played once and once only."

The last guy writing about his Apple Mail experience says he couldn't find a solution either. According to his post, however, Apple is "aware" of the problem and working on a fix.

Are you having any "incoming mail sound" issues?