You cannot. Such reporting does not exist. There is a weekly summary that is sent each Sunday (or Monday) at 3AM but I have found it to not be very helpful personally.
HOWEVER this does NOT mean that the capabilities or data is not already there. I have made an unsupported modification to my setups by adding pflogsumm. I just review it on demand from the command line, but it is very simple to set this up to send a daily report via email if you so desired.
Sample output:
Postfix log summaries for Jul 25
Grand Totals
messages
338 received
370 delivered
0 forwarded
1 deferred (1 deferrals)
2 bounced
398 rejected (51%)
0 reject warnings
0 held
0 discarded (0%)
4674k bytes received
4885k bytes delivered
11 senders
9 sending hosts/domains
75 recipients
19 recipient hosts/domains
Per-Hour Traffic Summary
time received delivered deferred bounced rejected
--------------------------------------------------------------------
0000-0100 6 8 0 0 9
0100-0200 10 10 0 0 9
0200-0300 6 10 0 0 15
0300-0400 3 3 0 0 22
0400-0500 15 15 0 0 10
0500-0600 7 7 0 0 7
0600-0700 2 10 0 0 10
0700-0800 11 13 0 1 12
0800-0900 14 16 0 0 11
0900-1000 22 22 0 0 12
1000-1100 28 30 0 0 12
1100-1200 32 32 0 0 11
1200-1300 15 15 0 0 8
1300-1400 20 20 0 0 26
1400-1500 20 27 0 0 36
1500-1600 18 18 0 0 28
1600-1700 16 16 0 0 25
1700-1800 25 28 0 0 38
1800-1900 14 13 0 0 23
1900-2000 8 9 1 0 20
2000-2100 15 15 0 0 13
2100-2200 12 12 0 0 15
2200-2300 9 11 0 1 10
2300-2400 10 10 0 0 16
Host/Domain Summary: Message Delivery
sent cnt bytes defers avg dly max dly host/domain
84 1102k 0 3.8 s 9.6 s yahoo.com
38 476937 0 1.7 s 2.8 s gmail.com
24 537k 0 2.7 s 5.6 s hotmail.com
Beyond this point, the data is confidential, but if you wish to see a full sample output look at: https://www.server-world.info/en/note?os=Ubuntu_18.04&p=mail&f=9