add a "mail-to" link under the tree on the left

The link should be around "send"

Please send as many remarks, improvement suggestions and feeback as you want : it will directly be sent to the Studio core team for which your experience really matters. Try to add context to your feedback so that we get what you mean. Note that bugs should be reported there: https://jira.nuxeo.org/browse/SUPNXS for better tracking.