Why am I unable to share forms with sub-user accounts?

Não está chegando nenhuma mensagem de compartilhamento de formulário nos e-mails que estou cadastrando para o compartilhamento, apesar de não ultrapassar o limite de usuários que o plano permite (3).

You currently have two sub-user accounts. The email address of one of the sub-user accounts has been added into our bounce list and this is the reason why he's not getting the invitation email.

*********@ifrn.edu.br is IN Remove the bounce list 

Reason(s) : smtp; 550 5.7.1 External client with IP address 54.240.11.38 does not have permissions to submit to this server.

I have already removed the address from our bounce list, but as you could see, we are being blocked by the hosting so make sure to whitelist Jotform to prevent this from happening again in the future. To whitelist, please refer to our list here: https://www.jotform.com/help/145-Whitelisting-JotMails-IP-Addresses.

To know more about the bounce email thing, please check this guide: 

https://www.jotform.com/help/208-How-to-Prevent-Email-Bouncing-Related-Issues 

As for the sub-user accounts, both emails are registered already. Please ask them to login in order to view the shared forms. If you want to add one more sub-user, please do so in the Users tab. If the sub-user won't get the invitation, let us know the email address so we can check the bounce list. Or, do check it in your account. Here's how: https://www.jotform.com/help/262-How-to-Remove-Your-Email-Address-from-Bounce-List.