Some messagesID in the CMN log file ends in @*.* (4294522)

The messages are delivered properly but CMN log file shows the following details about the message:
 INFO  CMN.logging [13] - Message Number [6] on Thread [13] from Domino (111.11.11.11:4757) to Exchange (11.1.1.1:25): Processed Message ID: OF5A5C60E7.7C478629-ON85257ACB.0075FCB7-85257ACB.007608D7@*.* - Size: 946 - From: username@domain.com - To: username2@exchange.domain.com - Processing Time: .068 Seconds - Changes: NoChange

CMN MailCon does not control the messageIDs. These messages are sent from the source Domino server and Domino server is inserting these messageIDs.

Usually, some kind of UID followed usually by @server domain name. However, source Domino server seems to be inserting  *.* instead.

This should not matter since the messageIDs still be unique between the messages and messages should be delivered.