How do I turn off repeated email alerts?

[Raymond Moul]

I'm using the stock email app that came with the att htc 1x, and when I get an email my phone will make a noise. If I don't check the email immediately, I'll get another noise later for the same email.

I'd like to be able to turn off the duplicate sound notifications, but can't seem to find a setting for it.

Has anyone been able to turn this off?