Yes, a1.tch.harvard.edu can receive emails.
Yes, a1.tch.harvard.edu seems to be a legitimate domain.
A record
None
MX records
mailsmtp1.childrenshospital.org.
134.174.13.91
mailsmtp2.childrenshospital.org.
134.174.13.92
mailsmtp3.childrenshospital.org.
134.174.20.73
mailsmtp4.childrenshospital.org.
134.174.13.55
mailsmtp5.childrenshospital.org.
134.174.13.56
mailsmtp6.childrenshospital.org.
134.174.20.74
mailsmtp7.childrenshospital.org.
134.174.20.50