Changing Welcome Message for courses purchased in Hikashop

With shop integration, Joomdle sends out a 'welcome' email when someone joins a course. In Joomdle I can change the message, but where do I change the reply to and sent from email address or how do I disable that message?

Thanks.

Reply/sent from is taken from Joomla configuration.

At this point, you can not disable sending the email, atlthough we sure should add the option for next Joomdle release.
If you want to disable email sending now, you will need to modify plugin code. If you want to do it, please let me know and I will give instructions on how to do it (it's easy, just need to comment out a line)