Hi,
The order is not processed, the order is just created.
So you receive an email to informed that the order has been created but with the default status (which should be "created").
Then, when the customer will pay the order, Authorize.net will confirm the payment and the order will be changed to "confirmed" (or other status depending your payment plugin config).
Because Authorize.net requires an order id, HikaShop must create an order, to get the ID and all other useful information.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.