Never, ever use Punchbowl. Half the invitations I sent out never reached the recipients. I double-checked that the email addresses were correct. By the time I figured out what happened, people couldn't make it because of too short notice. Punchbowl sucks.
We understand how important it is to gather friends and family to celebrate your most important occasions, and we're very sorry to hear you didn't have a great experience. We explain what to do in the rare occurrence that a guest doesn't receive their invite here: https://help.punchbowl.com/article/486-some-of-my-guests-didnt-receive-their-invitation-what-can-i-do and we make it very clear on the Manage Guests page which of your guests has viewed or has not viewed the invite.