How to generate response time conversation report?
The Conversation reports are used to find the response time of each mailitem. The "Response time report for Mailbox" report of Conversation allows single mailbox to be selected to check for response time
and "Response time report for Distribution Group" report of Conversation allows single distribution group to be selected to process each member's mailbox.
Perform the following steps to generate a Conversation Report:
Select Exchange Online Reports from the available vertical tabs. Then from left pane of application, select Conversation.
On the selection of "Response Time Report for Mailbox" from the list of available reports, a dialog is displayed as shown below:

Likewise, a dialog is displayed on the selection of "Response Time Report for Distribution" report of Conversation as shown below:

On selecting the desired mailbox/distribution group and other required field, the resultant data are displayed in a window as shown below: