Sub Expire_New()

    Dim arr()       As Variant
    Dim msg(1 To 4) As String
    Dim x           As Long
    Dim dDiff       As Long

    With ActiveSheet
        x = .Cells(.Rows.Count, 19).End(xlUp).Row
        arr = .Cells(21, 1).Resize(x - 20, 26).Value
    End With

    For x = LBound(arr, 1) To UBound(arr, 1)
        If Len(arr(x, 19)) * Len(arr(x, 1)) * Len(arr(x, 2)) Then
            dDiff = DateDiff("d", Date, arr(x, 19))
            Select Case dDiff
                Case Is <= 0: msg(1) = Expired(msg(1), arr(x, 1), arr(x, 2), arr(x, 19))
                Case Is <= 31: msg(2) = Expiring(msg(2), arr(x, 1), arr(x, 2), arr(x, 19), dDiff)
            End Select
        End If

    If Len(arr(x, 19)) = 0 And Len(arr(x, 1)) > 0 And Len(arr(x, 2)) > 0 Then
             msg(3) = NoTraining(msg(3), arr(x, 1), arr(x, 2), arr(x, 18))
        End If

    If Len(arr(x, 19)) > 0 And Len(arr(x, 1)) > 0 And Len(arr(x, 2)) > 0 Then
   dDiff = DateDiff("d", Date, arr(x, 19))
        Select Case dDiff
         Case Is > 31: msg(4) = MsgBox("There are either no expired safeguarding certificates, or no certificate expiring within the next 31 days.", vbCritical, "Warning")
        End Select
    End If

    Next x

    For x = LBound(msg) To UBound(msg)
        msg(x) = Replace(msg(x), "@NL", vbCrLf)
        If Len(msg(x)) < 1024 Then
            MsgBox msg(x), vbExclamation, "Safeguarding Certificate Notification"
        Else
            MsgBox "String length for notification too long to fit into this MessageBox", vbExclamation, "Invalid String Length to Display"
        End If
    Next x

    Erase arr
    Erase msg

End Sub

Private Function Expired(ByRef msg As String, ByRef var1 As Variant, ByRef var2 As Variant, ByRef var3 As Variant) As String

    If Len(msg) = 0 Then msg = "Persons with EXPIRED Safeguading Certificates@NL@NL"

    Expired = msg & "(@var3) @var1 @var2@NL"
    Expired = Replace(Expired, "@var1", var1)
    Expired = Replace(Expired, "@var2", var2)
    Expired = Replace(Expired, "@var3", var3)

End Function

Private Function Expiring(ByRef msg As String, ByRef var1 As Variant, ByRef var2 As Variant, ByRef var3 As Variant, ByRef d As Long) As String

    If Len(msg) = 0 Then msg = "Persons with EXPIRING Safeguarding Certificates@NL@NL"

    Expiring = msg & "(@var3) @var1 @var2 (@d days remaining)@NL"
    Expiring = Replace(Expiring, "@var1", var1)
    Expiring = Replace(Expiring, "@var2", var2)
    Expiring = Replace(Expiring, "@var3", var3)
    Expiring = Replace(Expiring, "@d", d)

End Function

Private Function NoTraining(ByRef msg As String, ByRef var1 As Variant, ByRef var2 As Variant, ByRef var3 As Variant) As String

    If Len(msg) = 0 Then msg = "SAFEGUARDING TRAINING NOT COMPLETED FOR @NL@NL"

    NoTraining = msg & " @var1 @var2@NL"
    NoTraining = Replace(NoTraining, "@var1", var1)
    NoTraining = Replace(NoTraining, "@var2", var2)
    NoTraining = Replace(NoTraining, "@var3", var3)

End Function

If Len(arr(x, 19)) > 0 And Len(arr(x, 1)) > 0 And Len(arr(x, 2)) > 0 Then
   dDiff = DateDiff("d", Date, arr(x, 19))
        Select Case dDiff
         Case Is > 31: msg(4) = MsgBox("There are either no expired safeguarding certificates, or no certificate expiring within the next 31 days.", vbCritical, "Warning")
        End Select
    End If