I need a script that tells you if a string is a valid email address.

contains one "@" symbol, and has at least one period after the "@" symbol.

This is a simple function I have been using in PHP for years.
Feel free to derive it in asp:

PHP Code:

function is_email($e){
// returns true if it's an email address.
// returns false if it's not.
  if (eregi("^([a-z0-9_]|\\-|\\.)+@(([a-z0-9_]|\\-)+\\.)+[a-z]{2,4}\$", $e)==1){   
    return true;
  }
  else{
    return false;
  }
} 


function CheckMail(strIn)
 dim objRE
  Set objRE = New RegExp
  objRE.Pattern = "^[a-zA-Z][\w\.-]*[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$"
  objRE.IgnoreCase = true
  CheckMail = objRE.Test(strIn)
set objRE = Nothing
end function

or a dead simple one

function CheckEmail(strEmail)
dim temp
temp = false
if len(strEmail) > 6 then temp = true
	if temp then 
		if (instr(strEmail,"@") < 2 or instr(strEmail,".") = 0) then
			temp = false
		else
		if instr(instr(strEmail,"@"),strEmail,".") = 0 then
			temp = false
		end if		
		end if
	end if
CheckEmail = temp 
end function

How about that for efficiency?

converted from PHP to ASP in under two minutes

Good work Chris !

Thank you!