Hi there
I just completed a Exchange 2007 to Exchange 2013 (CU2-v2) migration for one of my customers (Ex2007 gacefully decommissioned and correctly uninstalled). We are running into two issues yet. One of these issues is about Delivery Receipt.
I was able to reproduce this problem in a separate pilot environment and I don't really understand where the issue could be.
If users send messages with "Delevery Receipt" option (for both Intra-Organization and Extra-Organization recipients), the receipt is correctly delivered to senders. But... if users send a message with a large attachment (ie: 10 MB), the messages are delivered but receipts will not return back to senders as expected. This problem does not show up with small attachments (about 1 or 2 MB). I don't know which is the threshold for this, but I see that 3 or 4 MB messages will correctly return Delivery Receipts to senders, while messages larger than 5 or 6 MB will not generate Delivery Receipts after messages are correctly delivered.
Anyone knows if this is a known issue?