Thank you for the instructions of uninstall > reboot > reinstall.
Without the reboot in the middle, I was continuing to have this problem
just by uninstalling/reinstalling.
I think it's impossible now. The two tricks that I knew (either
generating a packing slip or replying to a Paypal payment email) have
both been either upgraded or deprecated to remove email addresses
entirely.
Unfortunately it looks like eBay finally killed this loophole, which is
a shame for buyers. I'm an international seller that uses registered
shipping and I used this feature to send tracking updates directly to
buyers' emails.
