Seeking Correct Regex String for Valid E-mail Addresses

To test for valid e-mail addresses I've long been using the following one which I found who-knows-where long ago:
              Regex objValidEmailPattern = new Regex(@".*@.*\..*");
I thought it worked perfectly but a QA person just discovered that you can enter any number of "@" symbols, which is clearly not valid.  For example, the following string is considered valid by the aforementioned Regex:  abc@@def.com
Can anyone recommend a better Regex string that I should use?
Robert
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