I looked into our servers and all of the emails are being shown as delivered, none have been bounced/returned. It sounds as if it is being filtered somewhere in your system but as you mentioned you have check all of your mail folders.
I am discussing this internally to determine if there is a possible work-around.
I have created an account with an address like "firstname.lastname@example.org". I did not receive any confirmation email... It was also not possible for me to register to Jive using this email address. It considers the address it is not valid (I think the Regex was not uploaded).
Could you help me please?
All the best,