How to turn off notifications for conversation messages

Conversations don't use the notification preference manager framework. To disable conversation notifications you've got to disable a profile option.

The profile option ORA_SVC_ENABLE_CONV_MSG_NOTIFICATION is enabled by default. This profile option includes the following profile values which are listed in a comma-separated list:

ORA_HZ_ORGANIZATION_PROFILES
ORA_MKL_LM_LEADS
ORA_MOO_OPTY
ORA_SVC_SERVICE_REQUESTS
ORA_SVC_SERVICE_REQUESTS_HRHD
ORA_SVC_SERVICE_REQUESTS_ISR
ORA_ZMM_ACTY_ACTIVITIES
ORA_SVC_CASES

When this profile option includes the code for an object, such as Opportunity, a conversation message is sent and the recipient of the message automatically receives a bell notification.

If you don't want these bell notifications to appear for any of the objects listed, find the object code in the comma separated list in the profile values field, and delete them. To disable bell notifications for all conversation, you just need to disable the profile option.

Here's how you access the profile option:

From Setup and Maintenance, select the Tasks icon.
Search for and select Manage Administrator Profile Values.
On the Manage Administrator Profile Values page, search for ORA_SVC_ENABLE_CONV_MSG_NOTIFICATION into the Profile Option Code field.
In the profile value field, delete the profile option codes for the applications on which you don't want notifications.
Save and close.