I noticed that Approver of the expense claim is not receiving the email therefore I searched for ERPNext user manuals and if I am not wrong that the approver will not receive any email until the document is assigned to him. I appreciate if anyone let me know is there any setup to send email to user automatically without configuring the Email Alert.
Below is the text copied from ERPNext Documentation.
The person making the claim must also set the id of the user who will “Approve” these expenses and set the “Assign To” to notify the user of the request Approve.
If the Approver sees the “form”, she or he can update the “Approved Amounts” and click on “Approve”. To cancel the claim, they can click on the “Reject” button.
Comments can be added in the Comments section explaining why the claim was approved or rejected.