Delivery Confirmation Report- cannot find detail on messaging log

Hi,

Some of my users are getting 'Delivery Confirmation Report' though they have not chosen to get it. The Delivery Confirmation Report is coming from the Symantec messaging gateway, but when I check on the logs I do not find any detail about it. We use lotus notes and when I check email detail, I get below

received from messaginggateway ([17*.**.**.**]) by lotus notes sever (Lotus Domino Release) with ESMTP id ******

from [127.0.0.1] ([local]) by messaginggateway (envelope-from <>) (ecelerity 4.2.1.51032 r(Core:4.2.1.4)) with UNKNOWN id ***

How can I check on the symantec messaging gateway to know when these reports are being sent? I have users who are getting a lot of the reports. 

Thanks to help