I uploaded the extension to the store, and added email address for tester accounts. I published the extension to the testers. Now what will happen? I thought Google would send them invitation mails but clearly this is not the case.
ALso, how many tester accounts can we add?
I had the same problem (testers not being automatically notified) and found a solution/work-around:
Info source: https://developer.chrome.com/webstore/publish?csw=1#publishing-to-test-accounts