Deciding when and how the Close Conversation function should be used by team members will be unique to every team as marking a conversation as closed could mean different things to different teams.
The best way to help you determine when one of your team members needs to mark a conversation as closed is to explain how the metric is calculated and what happens when they do or do not use the close conversation option.
When a customer email first arrives in your mailbox, the conversation status = Awaiting Mailbox Response, once a team member replies the status changes to Awaiting Contact Response. The status will continue to switch between Awaiting Mailbox Response and Awaiting Contact Response as the email conversation continues back and forth. So if your goal is to deliver daily reporting on the number of conversations closed and the average time it takes your team to handle the customer query (total time for the entire conversation thread), regardless of whether the query has been resolved, then the team member can mark the conversation as closed after every reply.
If your goal is to measure total resolution time, and the number of conversations Awaiting Mailbox Response vs the number of conversations Closed, then your team need only mark a conversation as closed once there is no longer a need to reply to the customer. If the customer replies and simply says ‘thanks’, and the team member does not mark the conversation as closed, the conversation status will remain ‘Awaiting Mailbox Response’.
In the scenario where a team marks a conversation as closed and the customer or a colleague responds to the closed conversation, the conversation status will return to Awaiting Contact/Mailbox Response, depending on who was the last to reply.
In this case, the conversation will no longer be included in your avg Time To Close statistic, until it is marked as closed again and the system recalculates the Time To Close (The time elapsed from the First email in the thread to the last email in the thread when the thread was marked as closed).
There’s a lot of overlap between the scenarios listed above, but one way to think about whether you should mark as closed or not is to determine how important reporting on Awaiting Mailbox Response conversations vs Closed conversations is for your business.