Unable to receive mails wirelessly in 7130

I was using a 7130 in provided by a carrier in my home country and was connected to my corporate exchange server (thru BES). Now I have moved to Australia and wanted to use my handset with a sim from a carrier here (Telstra).

The issue i am facing is that I am unable to receive office emails (via BES) wirelessly. I am able to send emails thru this but NOT receive. Both sending and receving works fine when i am connected to my laptop (network) via USB.

I had contacted my BES Admin to check all possible permutation combinations like (checking all filter options etc) but so far no luck.

Could you any one kindly provider pointers to what could be the issue?

1. Try regenerating encryption key.
From menu go to Options -> Scroll and Select Security Options -> Select General Settings -> Scroll all the way down to services -> Press menu key and select Regenerate Encyption Key

2. Try wiping handheld and re-activating BES account on device
Note: If you are going to backup and restore contents just make sure tjo to do a partial restore.