Which module an email sent through workflow is related to?

I have a workflow related to a project task for sending and email when a field is updated. I’ve seen that the sent email then appears under history subpanel of module Account even though the project Task is not directly related to that Account.

I was wondering which is the criteria for sent email from workflow? And more, Is there a way to not save the email but just send it and then delete it?

Thanks

Currently there is no way to just send the email then delete it, So I think workflow will look for the related account to the project that the task is related to and use that.