they send email. Also I find I get the email notice and updated on account a day or two after they have been shipped.
I would find out faster that my unit was sent by notice from my UPS account. If your using UPS you need to open a free account with them and once Bitmain prints out a label you will be notified. I also use this account to change the delivery to my local UPS store so I don't miss the delivery if nobody is home to sign for it. Just stop at the UPS store after work and show my ID to pick up the package.