My question is, suppose you send up to 10 000 recipients per day, is there a way to display them in a report without messing up the page?
Yes. One way is to display information in a progressive fashion.
The top Level displays the primary reporting information and on drill-down present ever more detailed information.
You didn't mention it but there is much more information to display.
Amt in Email List | Emails Sent % | Emails Opened / % | Responses
10,000 | 1000 10% | 100 1% | 10
The chances of the manager just wanting to blindly scan a list of 10,000 is very low. You need to find out what specifically the person is trying to ascertain from the information.
Also if you're sending that many emails it is probably organized into campaigns. You may be sending the same email (or variations on a theme) multiple times to the recipient.