Hi stacey37. Thanks for joining the discussion here in the Community!

Packing slips are an essential asset for many businesses. The system has designed the Packing Slip option as a print-out that can be added to shipments. At this time, there isn't a direct method you can use to email your packing slip directly from QuickBooks Online. Don't worry, there's a great workaround you can use if some of your customers request an electronic copy.

When you click "Print Packing Slip", QBO will open a new tab where you can preview your slip before printing. In the upper right-hand corner, you'll see an option to download the document in order to save it to your computer. You can then add this as an attachment to an email outside the QuickBooks environment, via your email provider. 

I know this isn't exactly what you were looking for in terms of a solution, but I'm confident this will help you reach your ultimate goal. In the meantime, I'd also suggest submitting feedback about this to our product engineers. You can do that by clicking the Gear icon > Feedback. 

Take care.