For Xero-connected Organisations, you can set up a default email in ApprovalMax that will be sent to the customer automatically (not supported for trial customers).
This is how it works:
In the main menu on the left side, click on Approval workflows.
Open the Sales Invoice workflow.
Click on the Gear icon.
Scroll down to the settings for "Email to the customer".
Select "Enabled and checked".
Type in a default email address. You can also add multiple email addresses in the CC section; each one can be removed later in a Sales Invoice if required.
Set up a default email template.
Click on SAVE.