error 24 after sending mail

[John]

I found code beneath on the internet. It works well, except for one thing.
After the email has been sent I get the error message:

"error 424 while executing
Ojbect demanded"

The line that is causing the error is "acc.Run MailParameters()"
I have no clue where to look. Anyone has an idea?

Thanks in advance,
john
Public Function MailParameters()
Dim outApp As Outlook.Application, outMsg As MailItem
Set outApp = CreateObject("Outlook.Application")
Set outMsg = outApp.CreateItem(olMailItem)
With outMsg
'.Importance = olImportanceHigh
.To = "te**@test.nl"
'.CC = "CC EMAIL ADDRESS GOES HERE"
'.BCC = "BCC EMAIL ADDRESS GOES HERE"
.Subject = "YOUR SUBJECT GOES HERE"
.Body = "YOUR_E-MAIL_MESSAGE_GOES_HERE"
.Attachments.Add "D:\grootboek.txt"

' If you want to edit before sending
'.Display
'otherwise, to just send without looking...
.Send
End With

Set outApp = Nothing
Set outMsg = Nothing
End Function

Private Sub Knop96_Click()

acc.Run MailParameters()

End Sub