I'm glad you like jsreport software!
At this moment, you should send emails from the jsreportonline using a service that has a plain HTTP API.
The jsreportonline supports to require request module which you can do to invoke HTTP call to your email service.
We concentrate on jsreport integration and don't implement customer's scripts as part of the support. This is a business logic you should be able to maintain.
With jsreport v3, we will let you install custom modules in jsreportonline, but that will ship to jsreportonline the next year, so if you aren't in rush... However can't promise any exact timeline for the jsreportonline transition.