Code:
Sub Send1Sheet_ActiveWorkbook()
'Create a new Workbook Containing 1 Sheet (left most) _
 and sends as attachment.
 
    'ThisWorkbook.Sheets(1).Copy
    
    Range("A4:F58").Select
    Selection.Copy
    Workbooks.Add Template:="Arbeitsmappe"
    Range("A2").Select
    ActiveSheet.Paste
    Selection.PasteSpecial Paste:=xlValues, Operation:=xlNone, SkipBlanks:= _
        False, Transpose:=False
    Cells.Select
    Cells.EntireColumn.AutoFit
    Cells.EntireRow.AutoFit
    Range("B10").Select
    
    Range("A1:F1").Select
    With Selection.Interior
        .Pattern = xlLightDown
        .PatternColorIndex = xlAutomatic
        .Color = 255
        .TintAndShade = 0
        .PatternTintAndShade = 0
    End With
    
    
    
    Range("D1:D58").Select
    Selection.ClearContents
    Range("C1").Select

    
    With ActiveWorkbook
         .SendMail Recipients:="[email protected]", _
          Subject:="Guten Morgen" & " - " & Format(Date, "dd/mmm/yy")
         .Close SaveChanges:=False
    End With
    
    Windows("Euribor_neu.xlsm").Activate
    ActiveWorkbook.Close True
    
End Sub