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



% [whois.apnic.net]
% Whois data copyright terms    http://www.apnic.net/db/dbcopyright.html

% Information related to '204.75.18.0 - 204.75.19.255'

% Abuse contact for '204.75.18.0 - 204.75.19.255' is 'abuse@fastmail.com'

inetnum:        204.75.18.0 - 204.75.19.255
netname:        FASTMAILPTYLTD-AU
descr:          Fastmail
country:        AU
org:            ORG-FA47-AP
admin-c:        FPLA12-AP
tech-c:         FPLA12-AP
abuse-c:        AF708-AP
status:         ASSIGNED PORTABLE
remarks:        --------------------------------------------------------
remarks:        To report network abuse, please contact mnt-irt
remarks:        For troubleshooting, please contact tech-c and admin-c
remarks:        Report invalid contact via www.apnic.net/invalidcontact
remarks:        --------------------------------------------------------
mnt-by:         APNIC-HM
mnt-routes:     MAINT-FASTMAILPTYLTD-AU
mnt-irt:        IRT-FASTMAILPTYLTD-AU
geofeed:        https://data.fastmail.com/data/geofeed.csv
last-modified:  2026-04-27T07:10:51Z
source:         APNIC

irt:            IRT-FASTMAILPTYLTD-AU
address:        Level 2, 114 William Street, Melbourne Victoria 3000
e-mail:         abuse@fastmail.com
abuse-mailbox:  abuse@fastmail.com
admin-c:        FPLA12-AP
tech-c:         FPLA12-AP
auth:           # Filtered
remarks:        abuse@fastmail.com was validated on 2025-11-11
mnt-by:         MAINT-FASTMAILPTYLTD-AU
last-modified:  2026-03-24T05:22:58Z
source:         APNIC

organisation:   ORG-FA47-AP
org-name:       Fastmail
org-type:       LIR
country:        AU
address:        Level 2, 114 William Street
phone:          +61457416436
e-mail:         apnic@role.fastmailteam.com
mnt-ref:        APNIC-HM
mnt-by:         APNIC-HM
last-modified:  2023-09-05T02:18:35Z
source:         APNIC

role:           ABUSE FASTMAILPTYLTDAU
country:        ZZ
address:        Level 2, 114 William Street, Melbourne Victoria 3000
phone:          +000000000
e-mail:         abuse@fastmail.com
admin-c:        FPLA12-AP
tech-c:         FPLA12-AP
nic-hdl:        AF708-AP
remarks:        Generated from irt object IRT-FASTMAILPTYLTD-AU
remarks:        abuse@fastmail.com was validated on 2025-11-11
abuse-mailbox:  abuse@fastmail.com
mnt-by:         APNIC-ABUSE
last-modified:  2025-11-11T16:35:37Z
source:         APNIC

role:           Fastmail Pty Ltd administrator
address:        Level 2, 114 William Street, Melbourne Victoria 3000
country:        AU
phone:          +61457416436
e-mail:         abuse@fastmail.com
admin-c:        FPLA12-AP
tech-c:         FPLA12-AP
nic-hdl:        FPLA12-AP
mnt-by:         MAINT-FASTMAILPTYLTD-AU
last-modified:  2021-06-21T02:31:27Z
source:         APNIC

% Information related to '204.75.18.0/23AS151847'

route:          204.75.18.0/23
origin:         AS151847
descr:          Fastmail Pty Ltd
                Level 2, 114 William Street
mnt-by:         MAINT-FASTMAILPTYLTD-AU
last-modified:  2026-04-29T05:09:16Z
source:         APNIC

% This query was served by the APNIC Whois Service version 1.88.48 (WHOIS-AU4)