Vba msgbox show only once - vba

Question

Is it possible to make the msgbox of this code to appear only once? My problem is that if the user inserts data i.e. from row 501 until 510 the message box will appear 9 times, and I want to have it only once. The reason of this is because the code looks in each cell to verify if something is inserted, and then the content is deleted and the msg appears. If it is possible I would like to keep the format of the code below, but only to show the msgbox once. If not, any suggestions would be welcomed.
Private Sub Worksheet_Change(ByVal Target As Range)
Dim cell22 As Range
Application.EnableEvents = False
For Each cell22 In Target
If Not Application.Intersect(cell22, Range("a501:z6000")) Is Nothing Then
If cell22.Value <> "" Then
cell22.ClearContents
MsgBox "You cannot insert more than 500 rows", vbInformation, "Important:"
End If
End If
Next cell22
Application.EnableEvents = True
End Sub

Answer 1

I would suggest another way.
The tasks which access the worksheet, such as ClearContents takes the longer to process.
So instead of clearing the contents each time inside the loop for a single cell, and repeat it a few hundred times, use ClrRng as a Range object. Every time the If criteria is met, you add it to ClrRng using the Application.Union function.
Once you finish looping through all your cells, clear the entire cells in ClrRng at the same time.
Code
Private Sub Worksheet_Change(ByVal Target As Range)
Dim cell22 As Range, b As Boolean
Dim ClrRng As Range ' define a range to add all cells that will be cleared
Application.EnableEvents = False
For Each cell22 In Target
If Not Application.Intersect(cell22, Range("A501:Z6000")) Is Nothing Then
If cell22.Value <> "" Then
If Not ClrRng Is Nothing Then
Set ClrRng = Application.Union(ClrRng, cell22)
Else
Set ClrRng = cell22
End If
End If
End If
Next cell22
If Not ClrRng Is Nothing Then ' make sure there is at least 1 cell that passed the If criteria
ClrRng.ClearContents ' clear all cell's contents at once
MsgBox "You cannot insert more than 500 rows", vbInformation, "Important:"
End If
Application.EnableEvents = True
End Sub

Answer 2

Try this:
Option Explicit
Private Sub Worksheet_Change(ByVal Target As Range)
Dim cell22 As Range
Application.EnableEvents = False
For Each cell22 In Target
If Not Application.Intersect(cell22, Range("a501:z6000")) Is Nothing Then
If cell22.Value <> "" Then
cell22.ClearContents
GoTo displayMsg
End If
End If
Next cell22
Application.EnableEvents = True
Exit Sub
displayMsg:
MsgBox "You cannot insert more than 500 rows", vbInformation, "Important:"
Application.EnableEvents = True
End Sub

Answer 3

This will only show it once but clear each cell which is non-blank.
Private Sub Worksheet_Change(ByVal Target As Range)
Dim cell22 As Range, b As Boolean
Application.EnableEvents = False
For Each cell22 In Target
If Not Application.Intersect(cell22, Range("a501:z6000")) Is Nothing Then
If cell22.Value <> "" Then
cell22.ClearContents
b = True
End If
End If
Next cell22
If b Then MsgBox "You cannot insert more than 500 rows", vbInformation, "Important:"
Application.EnableEvents = True
End Sub