ISP SMTP Server
ABC Net mail.hkabc.net
CTI smtp3.ctimail3.com
HGC mail.on-nets.com
HKBN smtpo.hkbn.net
HKC smtp.hkcmail.com
HKNet smtp.hknet.com
I-Cable smtp.i-cable.com
iSmart smtp.ismart.net
NET Front mail.netfront.net
Netvigator mail.netvigator.com, corpmail1.netvigator.com
OneBB smtp.onebb.net
Pacific Supernet smtp.pacific.net.hk
So-net smtp.so-net.com.hk