I achieved to run it properly by using gmail by applying connection settings manually (without clicking 'Use Global Settings' checkbox and entering each detail in Connection tab for EmailService component). But, what I want to know is configuring global outgoing email settings for all processes. At the end, it will make an email accont to be used for all process by default.
I tried to configure email server settings at adminui application, but I got the same error. Then, I added a default email endpoint and again I got the same error. So far, I need to configure each EmailService component's connection settings one by one, which is not common once considering business process development.
The Server Settings located in adminui are not the ones used for Global Settings on the Email service.
(The ones set in the adminui are used for notifications of Workspace Task Assignments.)
Here's where you need to set the Global Settings:
1) In Workbench, choose Window->Show View->Components.
2) Expand the components.You will see 2 components titled Email.
3) Choose the second one. Expand Active Services. You should see "EmailService:1.0."
4) Right click on the EmailService:1.0 and choose "Edit Service Configuration".
5) Add your values and then Stop/Start the service.
These values will be used in your Email Service if you select Use Global Settings.
Hope this helps.