go
mail.bc.bw are subdomains to this hostname.

bw
ns-soa records
ns1.btc.bw
+ 168.167.168.34 168.167.0.0/16 AS14988 -
+ --- -
ns records
hippo.ru.ac.za
+ 146.231.128.1 146.231.0.0/16 AS2018 -
+ --- -
rain.psg.com
+ 147.28.0.34 147.28.0.0/16 AS3130 -
ns1.btc.bw
+ 168.167.168.34 168.167.0.0/16 AS14988 -
ns4.btc.bw
+ 168.167.253.20 168.167.253.0/24 AS14988  
+ ---  
vpsm.btc.bw
+ 168.167.253.21 168.167.253.0/24 AS14988 -
+ --- -
subdomains
mail.bc.bw