They definitely will not. After our box was hit twice, I re-installed the third one a bit farther back from the curb. Within a week, I'd received notice that the box was out of compliance (by 2 inches) and mail delivery would cease within a week if it wasn't relocated. In fairness to USPS' fastidiousness, I did know it was outside guidelines, and decided to risk it...which did not pan out.
Some helpful links:
https://www.usps.com/manage/mailboxes.htm
https://about.usps.com/publications/engineering-standards-specifications/spusps-std-7b01/welcome.html
In other words, building your own box may be way more trouble than it's worth. FWIW, according to USPS guidelines, mailbox mounts should be breakaway. The brick surround may violate this caveat.