Powershell script not recognizing my function

Powershell processes in order (top-down) so the function definition needs to be before the function call:

function email($text){    #email $text}#Do things | foreach{    email($_)}

It probably works fine in the ISE because you have the function definition in memory still from a prior run or test.

When it comes to the Function-Calls, PowerShell is fairly different from other programming-languages in the following ways:

1. When passing the arguments to a function, parentheses are NOT allowed (and will raise a parse error if Set-StrictMode is set to -version 2.0 or above/Latest), however, Parenthesised arguments must be used to call a method, which can either be a .NET method or a user defined method (defined within a Class - in PS 5.0 or above).
2. Parameters are space-separated and not comma separated.

3. Be careful in where you define the function. As PowerShell sequentially processes line-by-line in top-down order, hence the function must be defied before that function is called:

       Function func($para1){          #do something    }    func "arg1"  #function-call

In ISE, function defined below the function-call may appear as working but (beware) it's the cached function definition in memory from a previous run, so if you have updated the function you are screwed.