Click on the 
menu at
the top of the screen
To change a Workflow Manager Mailbox configuration you need to have Manage Workspace Mailbox - Workspace Level Privilege.
The following steps should be used to change an existing Workspace Mailbox configuration:
Click on the menu at
the top of the screen
Select Manage Workspace Mailbox
Click on the Workspace Mailbox name displayed in the list for which you want to change the configuration
Make the configuration changes required
You will not be able to change the address of the mailbox
Changes to the configuration will only apply on the
future mails being sent to the Mailbox and will not affect any of the
mails published in the folder earlier
Click on Save to save the Workspace Mailbox configuration
Useful Links:
Send Email to a Workspace Mailbox