Sends a Sales Invoice email. If "toAddress" is not empty then email will be sent to this address. Otherwise email will be sent to Sales Invoice Customer's address.

Example request

{
  "salesInvoiceId": 1,
  "toAddress": "to@email.com",
  "bccAddresses": [
    "bcc1@email.com",
    "bcc2@email.com",
    "bcc3@email.com"
  ],
  "messageBody": "Email message"
}