Need to save CSV from specific email/subject to network folder

[gmayor]

The way to do this is to create a rule that identifies the incoming message and runs a script. The only problem is that your employer may have disabled scripts and that will need a registry change to address - https://www.slipstick.com/outlook/ru...-script-rules/. You would need to liaise with your company IT support to address that. In any case you may need to create a certificate to run Outlook code - https://www.gmayor.com/create_and_em...gital_cert.htm.
The basic code would be

Sub SaveAttachments(olItem As MailItem)
'Graham Mayor - https://www.gmayor.com - Last updated - 02 Apr 2022
Dim olAttach As Attachment
Dim strFname As String
Dim i As Long
Const strSaveFldr As String = "D:\Path\Attachments\"    'the path where the csv is to be saved
    On Error Resume Next
    If olItem.Attachments.Count > 0 Then
        If InStr(1, olItem.Categories, "Processed") = 0 Then
            For i = 1 To olItem.Attachments.Count
                Set olAttach = olItem.Attachments(i)
                If olAttach.FileName Like "*.csv" Then
                    strFname = olAttach.FileName
                    olAttach.SaveAsFile strSaveFldr & strFname
                    olItem.Categories = "Processed"
                    Exit For
                End If
            Next i
        End If
        olItem.Save
    End If
lbl_Exit:
    Set olAttach = Nothing
    Set olItem = Nothing
    Exit Sub
End Sub

If for reasons indicated, you cannot run the script from a rule then while you could create an event to process the message as required, I find that this method is less reliable and in the absence of a rule I would instead create a rule to divert the messages as they arrive into a sub folder of inbox and then select the message and run the following macro to process the message, calling the code above.

Sub ProcessMessage()
Dim olMsg As MailItem
    On Error Resume Next
    Select Case Outlook.Application.ActiveWindow.Class
        Case olInspector
            Set olMsg = ActiveInspector.currentItem
        Case olExplorer
            Set olMsg = Application.ActiveExplorer.Selection.Item(1)
    End Select
    SaveAttachments olMsg
lbl_Exit:
    Exit Sub
End Sub