When an address is on the clipboard, ShipRush will automatically prompts if you want to ship:

This prompt disappears automatically after a few moments.
The clipboard is also checked for an address whenever the Blank Shipment option is selected from the ShipRush menu
How to Use Clipboard Shipping?
Ecommerce:
Copy Ship To addresses from the emails your web store sends you
Copy addresses from web pages, such as the ecommerce merchant console
Professional Services:
Copy from web sites and documents straight into ShipRush
General:
Great for ad hoc shipping in general!
Note that these shipments will appear in the View Shipments
area,
These behaviors can be turned off in Settings.