I have 2 sub procedures and 2 radio buttons. I want to create a macro that, when clicked, executes the Email_No_New if the first radio button is selected or executes Email_New if the second radio button is selected (the radio button selection are mutually exclusive.) I'm getting a "Sub or Function not defined" error on the 3rd line.

Sub GenerateEmail_Click()
    Dim ws As Worksheet
    Set ws = Worksheet("Calculator")
    If ws.Shapes("Option Button 1").Value = True Then
           Call EMail_No_New
    Else
        If ws.Shapes("Option Button 2").Value = True Then
            Call EMail_New
        End If
    End If
End Sub

Option Buttons

Form Controls

• To reference a member of the Worksheets collection, you need to use Worksheets(...) as mentioned by braX in your comments. To see the difference, in a sub write Worksheet(. Nothing will happen. Remove or out-comment the line. Then try Worksheets( and you will see that IntelliSense kicks in.
• Shapes don't have a Value property. In a sub, write the line Dim shp As Shape: shp.v and observe how it isn't offered by IntelliSense.
• When selected, an Option Button's value is 1 (not True). Otherwise, it's -4146 (not False).

A Quick Fix

Sub GenerateEmail_Click_QF()
    Dim ws As Worksheet: Set ws = ThisWorkbook.Sheets("Calculator")
    If ws.OptionButtons("Option Button 1").Value = 1 Then
        Email_No_New
    ElseIf ws.OptionButtons("Option Button 2").Value = 1 Then
        Email_New
    Else
        MsgBox "No option button selected!", vbExclamation
    End If
End Sub

An Improvement

• A With statement often makes the code more readable. A Select Case statement is often more appropriate than using (multiple) ElseIf statements (not so much in this case).

Sub GenerateEmail_Click()
    With ThisWorkbook.Sheets("Calculator")
        Select Case 1 ' 1 (selected); -4146 (not selected)
            Case .OptionButtons("Option Button 1").Value: Email_No_New
            Case .OptionButtons("Option Button 2").Value: Email_New
            Case Else: MsgBox "No option button selected!", vbExclamation
        End Select
    End With
End Sub

ActiveX Controls

• If you decide to use ActiveX controls instead of Form controls, the same would look like this:

Sub GenerateEmail_Click_ActiveX()
    With ThisWorkbook.Sheets("Calculator")
        Select Case True ' True (selected); False (not selected)
            Case .OLEObjects("OptionButton1").Object.Value: Email_No_New
            Case .OLEObjects("OptionButton2").Object.Value: Email_New
            Case Else: MsgBox "No option button selected!", vbExclamation
        End Select
    End With
End Sub

• The values of these controls are True or False. Also, note how their generic names are different (no spaces).