For Invoice Distributions

There is a Setting in Admin > General Settings > Invoice Documents tab

Tick Email Invoices/Receipts for Invoices Generated from Invoice Distribution.

When the above configuration is set, and an invoice distribution is performed, if the "post to proforma" option is selected, a proforma document is generated for each invoice. If the "post to vat" option is selected a vat invoice document is generated.

The invoice documents are emailed to the invoice contact, unless the setting "Queue invoice generated emails for approval before sending" is set, then emails will be queued.

If the contact doesn't have an email address, in all cases, the document will be printed.

For Manual Invoices

There is a Setting in Admin > General Settings > Invoice Documents tab

Tick Email Invoices/Receipts when Manually Generated

When the above setting is set, and the user manually creates a sales invoice, if the "post to proforma" option is selected a proforma document is generated for each invoice. If the "post to vat" option is selected a vat invoice document is generated for each invoice.

The invoice documents will be emailed to the invoice contact. If the setting "Queue invoice generated emails for approval before sending" is set, the emails will be queued.

If the contact doesn't have an email address, in all cases, the document will be printed.

Note:

This functionality only applies to sales invoices and not credit notes.