[otrs] Email notifications

Hi there again, Among all users requests I have one that seems revelant to them ... They want to receive notification about an email sent through OTRS ... I mean they do an "empty answer" to a ticket, click on submit and would love to have a notification when the customer reads the email .... ala OUTLOOK Is that feature possible? Many thanks Phil World Intellectual Property Organization Disclaimer: This electronic message may contain privileged, confidential and copyright protected information. If you have received this e-mail by mistake, please immediately notify the sender and delete this e-mail and all its attachments. Please ensure all e-mail attachments are scanned for viruses prior to opening or using.