Yes, 53.capital can receive emails.
Yes, 53.capital seems to be a legitimate domain.
A record
None
MX records
alt1.aspmx.l.google.com
64.233.186.26
alt2.aspmx.l.google.com
209.85.202.26
alt3.aspmx.l.google.com
74.125.71.27
alt4.aspmx.l.google.com
108.177.126.27
aspmx.l.google.com
173.194.204.27