Microsoft Exchange New Mail Notification (NEWMAIL)

Microsoft Exchange e-mail servers use a protocol that Wireshark refers to as "NEWMAIL" to notify clients (such as Microsoft Outlook) that their mailbox has received a new e-mail message. The port is dynamically chosen by the client when logging in to the e-mail server and is transmitted in a MAPI Register Push Notification (mapi.opnum == 4) packet. Because the port is dynamically chosen, your packet capture must include the MAPI Register Push Notification packet in order to tie the newmail dissector to packets on that port. If you do not have the beginning of the connection in your capture file, you can right-click on the packet and choose "Decode As" and pick NEWMAIL from the list. NEWMAIL packets are always 8 bytes long with a destination UDP port > 1023.

Protocol dependencies

Example traffic

XXX - Add example decoded traffic for this protocol here (as plain text or Wireshark screenshot).


The NEWMAIL dissector is partially functional. The notification payload in the packets is displayed, but there is no public documentation that explains what the data stands for.

Preference Settings

The newmail protocol has one preference setting in Wireshark:

Example capture file

XXX - Add a simple example capture file to the SampleCaptures page and link from here (see below). Keep this file short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.


NEWMAIL (last edited 2008-04-12 17:51:35 by localhost)