Have gotten this error a couple of times now.
The customer receipt was not able to be delivered.Sendmail returned an error: Unknown error: 28416
A problem occurred sending an order notification to the merchant.Sendmail returned an error: Unknown error: 28416Unable to send order notification to the merchant.Sendmail returned an error: Unknown error: 28416
What exactly does this mean? Was the customer's email bad? Did the order go through? Is this a problem on our end?
Please help.