Out of office auto reply not sent to external recipient

Hi,

first to understand our setup

we have office 365 plan E3 --> we have configured smtp relay for all outgoing emails

                                          --> we have journaling enabled for all emails

now here the issue is any user enables or activates his or her out of office for internal and external emails, here is what happens

email received from internal user/id --> out of office auto reply is sent successfully

email received from external id --> out office auto reply is stuck in message queue in MS server

                                                --> when we did message trace it shows as email event as defer

                                                --> relay server does capture the email by journaling rule but                                                 actual out of office auto reply stuck in MS server queue. 

need help to sort this I do have case with MS about this but as my experience gona take very long time get reply from escalation team and support exec.

thanks

vaijnath c v