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Autonomous System

AS39588

Mimecast Services Limited

Announced IPs
2,560
CIDR prefixes
5
ASN
AS39588

Reputation · trust score

A transparent 0–100 signal. Every entity starts at a neutral baseline of 65; threat-intel blocklists, exposure, reverse-DNS, routing and allocation each adjust it up or down. Higher is more trustworthy.

53/100
Caution
How this score is built

Experimental · trust-vectors model v1.1.0 — a transparent heuristic, not a definitive verdict. How it works →

⚠ 4 MOAS prefixes — multiple origin ASNs detected

All MOAS anomalies →

A previously stable prefix originated by AS39588 is now also announced by another ASN (MOAS — Multiple-Origin AS), detected from our RIPE RIS collectors. Often benign (anycast, multi-homing, or a recent transfer) — but it can signal a route leak or prefix hijack, so it's worth inspecting.

PrefixOrigin ASNsLast detected (UTC)
170.10.142.0/24 AS39588, AS42427 2026-07-18 11:22:44
41.74.203.0/24 AS30031, AS33538, AS37235, AS39588, AS42427, AS136792 2026-07-18 11:22:44
216.145.218.0/24 AS30031, AS33538, AS37235, AS39588, AS42427, AS136792 2026-07-17 19:22:38
216.145.222.0/24 AS30031, AS33538, AS37235, AS39588, AS42427, AS136792 2026-07-17 19:22:38

Top CIDR ranges

CIDRIPsPTR DensityOrganizationCountryStateCity
194.104.108.0/22 1.0K
47.2%
Mimecast Services Limited DE
51.163.158.0/23 512
49.0%
Mimecast Services Limited GB
147.28.34.0/23 512
0.0%
Mimecast Services Limited GB
41.74.203.0/24 256
0.0%
ZA
62.140.7.0/24 256
92.6%
Mimecast Services Limited GB
62.140.10.0/24 256
5.9%
Mimecast Services Limited GB
216.145.218.0/24 256
0.0%
US
216.145.222.0/24 256
0.0%
US

BGP Announced Prefixes

Live BGP anomalies →

Prefixes AS39588 actually originates in BGP, observed across our RIPE RIS collectors. This live routing view can differ from the registry allocation above.

PrefixAnnouncement samplesLast seen
147.28.35.0/24 4,826 2026-07-18 10:51:58
147.28.34.0/24 4,776 2026-07-18 10:52:55
194.104.108.0/23 4,563 2026-07-18 10:52:55
62.140.10.0/24 4,550 2026-07-18 10:51:58
62.140.7.0/24 4,535 2026-07-18 10:51:58
194.104.110.0/23 4,441 2026-07-18 10:51:58
51.163.159.0/24 3,970 2026-07-18 10:52:37
51.163.158.0/24 3,968 2026-07-18 10:52:37
170.10.142.0/24 2,894 2026-07-18 10:01:46
216.145.222.0/24 2,816 2026-07-18 10:01:46
216.145.218.0/24 2,804 2026-07-18 10:01:46
41.74.203.0/24 2,643 2026-07-18 10:01:46

Frequently Asked Questions

What is AS39588?

AS39588 is an Autonomous System Number assigned to Mimecast Services Limited. An ASN identifies a network that controls a specific set of IP addresses and determines how traffic is routed across the internet via BGP (Border Gateway Protocol).

How many IP addresses does AS39588 announce?

AS39588 announces 2.6K IPv4 addresses distributed across 5 routed CIDR prefixes. The network is registered in United Kingdom.

Who operates AS39588?

AS39588 is operated by Mimecast Services Limited. The organization is based in United Kingdom. You can view all IP ranges and related ASNs on the organization page.

What country is AS39588 registered in?

AS39588 is registered in United Kingdom. This indicates where the network operator is headquartered, though the IP addresses it announces may serve users globally.

Last updated: 2026-07-18 11:25:31 UTC
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