I haven't found a way how to change workflow step automatically from (we are waiting for customer's reply) to (customer replied and he is waiting for our reply) in OnDemand Jira Service Desk when a requestor sends a comment through e-mail (we give no access to the web interface at the moment)
So far I found only Jira Toolkit plugin which seems to be installable only on self-hosted instances.
How to automate workflow transitions?