macro NOT WORK for cell value which contains formula(lookup)

I have a macro to send email from excel.
I have created a column "A" having email address, which infact is a lookup value from anotherworkbook.
My problem is when value in column A is manuelly entered, the macro runs & email is sent.
But when I use lookup formula in column A, macro gets run but no email is sent.
Any suggestion & Help. following is part of my macro.

[Dim OutApp As Object
    Dim OutMail As Object
    Dim cell As Range
Application.ScreenUpdating = False
    Set OutApp = CreateObject("Outlook.Application")
 On Error GoTo cleanup
    For Each cell In Columns("A").Cells.SpecialCells(xlCellTypeConstants)
        If cell.Value Like "?*@?*.?*" And _
           LCase(Cells(cell.Row, "U").Value) = "y" Then
Set OutMail = OutApp.CreateItem(0)
            On Error Resume Next
            With OutMail
                .To = cell.Value & ";" & cell.Offset(0, 2).Value
                'or .To = "91" & cell.Value & ";91" & cell.Offset(0, 2).Value
                .Subject = "Booking SMS"
                .Body = Cells(cell.Row, "AD").Value & vbNewLine & Cells(cell.Row, "AE").Value
                .Send  'Or use Display.
            End With
            On Error GoTo 0
            Set OutMail = Nothing
        End If
    Next cell]

Had this issue for days!!! SOLVED for me!!! THANK SO MUCH!!!