I face the same problem. I tested it using my e-mail a few times and no message was delivered. Finally I do not know whether any e-mails were sent out for my previous documents. I can only see that documents are not signed off.
We are not aware of any such issues. Can you send the list of email addresses you are sending the emails to AND the email from which the mail is sent so that we can have a look. Make sure to send the list in a personal message and not publish here.
I"m having the same issue. I'm preparing to transfer over to adobe for real estate so I tested a document to two users. (two of my own accounts). It would send it to one, but not the other. I don't want to make the switch if this is a glitch in the program.