Retrieval of lost emails

Hi,

I am currently having an issue with a user which has his own default exchange mailbox (@abc.com) and he is also a sole member of a distribution group which holds his name as email address so to have a secondary email address (@xyz.com).

The issue was that the user had requested that all incoming mail on his default exchange mailbox (@abc.com) will be forwarded on his secondary email address which is the distribution group. This forwarding was done on his exchange mailbox by setting Delivery options to forward all mail to @xyz.com which is the distribution group that forwards emails to his mailbox.

Basically what happened is that since the 'All forward change' was done no emails (both default mailbox and distribution) could be seen in his mailbox this basically happened as the emails sent to both addresses always redirects to his mailbox and since the distribution group forwards emails to his mailbox the mailbox will re-forward to the distribution group and holds this loop. I have mounted a Full Veeam Backup of his exchange mailbox but no emails during this period could be seen. The only thing I can see is the email details by opening the Exchange EMC Toolbox and make use of the message tracking.

Basically I would like to know my available options to retrieve these emails during this period (1.5 weeks)

Thanks
Karl