Made email Message-ID fields generated by the datatracker more uniform.

- Legacy-Id: 17360

ietf/utils/mail.py

@@ -61,7 +61,7 @@ def empty_outbox():
 
 def add_headers(msg):
     if not('Message-ID' in msg):
-        msg['Message-ID'] = make_msgid('idtracker')
+        msg['Message-ID'] = make_msgid()
     if not('Date' in msg):
         msg['Date'] = formatdate(time.time(), True)
     if not('From' in msg):
@@ -631,4 +631,4 @@ def get_payload(msg, decode=False):
         return msg.get_payload(decode=decode).decode(msg.get_content_charset('utf-8'))
     else:
         return msg.get_payload(decode=decode)
-        
+