thank you very much for your question. My name is***** and I will try to help you as quick possible.
Usually, if that is the case, you can´t do much about it, since 163.com might simply reject your email addresses. Would you allow me to send a test-email to that email address, so that I can see if it bounces for me too and being able to analyze the reason of the bounce?
Thanks for your patience and best regards,