Ecommerce "Contact Us" with anonymous login doesn't work after filling in email and all necessary info.
The root cause is the simple method "sendContactUsEmailToCompany" within
the file \applications\party\minilang\communication\CommunicationEventServices.xml has defined the field "sendFrom" as inputted email address from the anonymous users.
To fix it, it should be changed as follows:
<set field="emailParams.sendFrom" value="email@example.com"/>
While the email "firstname.lastname@example.org" should have been properly set up in your system.
It works for me!