It seems there’s more to the story! You’ve tried to sign in with three different email address (the same first part) at gmail.com, comcast.net and yahoo.com .
The reason for the gmail.com and comcast.net email not arriving is simply that you do not have an email with that address at gmail or comcast. Sorry, but not even we can send email to a non-existing email address!
It also seems that your sign-up with the yahoo.com address worked fine without trouble.
Good luck, and I hope that you’ll reconsider your recommendation to friends, but do tell everyone that it’s important to enter the right email address, one you actually can receive email to!