We have made an alternative solution on the server and mails should delivered to the recipient email id's. Kindly check it now and let us know if the problem still persists.
Some of my users on mail6 are getting bounced emails to Hotmail. I just had them send test emails to my Hotmail account and I they are not being received. I don't see mail6 on the MXToolBox blacklist. Any ideas what is occurring?