% APNIC found the following authoritative answer from: whois.apnic.net

% [whois.apnic.net]
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% Information related to '210.4.139.0 - 210.4.139.255'

% Abuse contact for '210.4.139.0 - 210.4.139.255' is 'inet-zimbra@inet.co.th'

inetnum:        210.4.139.0 - 210.4.139.255
netname:        DGA-TH
descr:          Digital Government Development Agency
country:        TH
admin-c:        NS755-AP
tech-c:         NS755-AP
abuse-c:        AO421-AP
status:         ASSIGNED NON-PORTABLE
mnt-by:         MAINT-TH-INET
mnt-irt:        IRT-ONEEMAIL-TH
last-modified:  2025-10-03T12:58:34Z
source:         APNIC

irt:            IRT-ONEEMAIL-TH
address:        Internet Thailand Company Limited
address:        1768 Thai Summit Tower, IT Fl.,
address:        Bang Kapi, Huay Kwang,
address:        Bangkok 10310
e-mail:         inet-zimbra@inet.co.th
abuse-mailbox:  inet-zimbra@inet.co.th
admin-c:        TY1494-AP
tech-c:         IP219-AP
auth:           # Filtered
remarks:        inet-zimbra@inet.co.th was validated on 2026-01-16
mnt-by:         MAINT-TH-INET
last-modified:  2026-01-16T04:08:09Z
source:         APNIC

role:           ABUSE ONEEMAILTH
country:        ZZ
address:        Internet Thailand Company Limited
address:        1768 Thai Summit Tower, IT Fl.,
address:        Bang Kapi, Huay Kwang,
address:        Bangkok 10310
phone:          +000000000
e-mail:         inet-zimbra@inet.co.th
admin-c:        TY1494-AP
tech-c:         IP219-AP
nic-hdl:        AO421-AP
remarks:        Generated from irt object IRT-ONEEMAIL-TH
remarks:        inet-zimbra@inet.co.th was validated on 2026-01-16
abuse-mailbox:  inet-zimbra@inet.co.th
mnt-by:         APNIC-ABUSE
last-modified:  2026-01-16T04:08:21Z
source:         APNIC

person:         Nattawat Saengmanee
address:        1768 Thai Summit Tower, 10-ITFl., New Petchaburi Road,Khwaeng Bang Kapi, Khet Huay Khwang, Bangkok 10310
country:        TH
phone:          +66-2257-7111
e-mail:         nattawat.sa@inet.co.th
nic-hdl:        NS755-AP
mnt-by:         MAINT-TH-INET
last-modified:  2022-06-08T09:23:43Z
source:         APNIC

% Information related to '210.4.139.0/24AS4618'

route:          210.4.139.0/24
origin:         AS4618
descr:          Internet Thailand Company Ltd.
                1768 IFCT Tower, 10th-12th FL
                IT Floor New Petchburi Road
                Khwaeng Bang Kapi
                Khet Huay Khwang
mnt-by:         MAINT-ITSC-AP
last-modified:  2020-11-24T08:40:00Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.34 (WHOIS-AU4)