Email Notifications from Process Chains are delayed

Hi,

Post Upgrade from 3.0B to 2004s we are facing this strange problem where the email alerts from the Process Chains are being delayed.

We now receive the Success/Failure emails atleast a couple of hours after the Process Chains complete the load whereas we used to receive them immediately pre-Upgrade.

So wanted to know if anyone faced similar kind of issue and whats the resolution for it?

Regards

Anujit Ghosh