Is the *Urgent* E-Mail Flag Completely Useless?

I get a lot of e-mail.  Some of it has that annoying red ! next to it signifying that it is urgent. Frankly, I only get urgent e-mails from two sources:

• Phisher’s for PayPal information
• Naive or misguided Mailing List members who think their questions deserve immediate attention (the same people who say, “I need an answer ASAP, PLEASE HELP!”

That got me thinking, since I never get actually useful e-mails that are marked urgent, it is useful at all any longer?  Does anyone actually use it effectively?