If the spelling of SubmissionTimestamp is correct (i.e. no space - as there are several spaces missing from your post) then the following function will give you the time and date that follows in a format that can be used as a filename:
Private Function GetName(olItem As MailItem) As String
Const strFind As String = "Exact SubmissionTimestamp: " 'Spelling must be exact!
Dim olInsp As Inspector
Dim wdDoc As Object
Dim oRng As Object
Dim strDate As String
With olItem
Set olInsp = .GetInspector
Set wdDoc = olInsp.WordEditor
Set oRng = wdDoc.Range
With oRng.Find
Do While .Execute(strFind)
oRng.collapse 0
oRng.End = oRng.End + 23
strDate = oRng.Text
strDate = Replace(strDate, Chr(58), Chr(95))
GetName = strDate & ".jpg"
Exit Do
Loop
End With
End With
lbl_Exit:
Set olInsp = Nothing
Set wdDoc = Nothing
Set oRng = Nothing
Exit Function
End Function
and you can call that from your macro e.g. as follows. Note that you need to limit the code to the file type.
Public Sub SaveAttachmentsToDisk(MItem As Outlook.MailItem)
Dim oAttachment As Outlook.Attachment
Dim sSaveFolder As String
Dim strFname As String
sSaveFolder = "C:\XXX\"
For Each oAttachment In MItem.Attachments
If oAttachment.fileName Like "*.jpg" Then
strFname = GetName(MItem)
oAttachment.SaveAsFile sSaveFolder & strFname
End If
Next oAttachment
Set oAttachment = Nothing
End Sub