Port 587 (SMTP)
HoneyLabs honeypots recorded 443 probes against destination port 587 (SMTP) from 184 distinct source IP addresses in the last 7 days.
First observed 2026-11-08 10:31, most recently 2026-11-15 08:13 (UTC).
What the sensors show
The sources sat in 30 networks across 17 countries. No single address sent more than 5% of them. The largest source network was AS135377 (UCLOUD INFORMATION TECHNOLOGY (HK) LIMITED), with 26% of the probes from 14 addresses. 3 of the 25 busiest addresses are recognised research scanners.
Most active source addresses
| Source IP | Probes | Network | Country |
|---|---|---|---|
| 3.129.187.38 | 20 | Amazon.com, Inc. | US |
| 18.218.118.203 | 13 | Amazon.com, Inc. | US |
| 18.116.101.220 | 11 | Amazon.com, Inc. | US |
| 128.1.132.17 | 9 | UCLOUD INFORMATION TECHNOLOGY (HK) LIMITED | HK |
| 106.75.24.130 | 9 | China Unicom Beijing Province Network | CN |
| 123.58.219.82 | 9 | UCLOUD INFORMATION TECHNOLOGY (HK) LIMITED | HK |
| 156.225.1.15 | 9 | AGOTOZ PTE. LTD. | HK |
| 156.225.1.16 | 9 | AGOTOZ PTE. LTD. | HK |
Networks it comes from
| ASN | Organisation | Probes | Source IPs |
|---|---|---|---|
| AS135377 | UCLOUD INFORMATION TECHNOLOGY (HK) LIMITED | 116 | 14 |
| AS15169 | Google LLC | 84 | 40 |
| AS16509 | Amazon.com, Inc. | 53 | 7 |
| AS14061 | DigitalOcean, LLC | 28 | 15 |
| AS396982 | Google LLC | 27 | 27 |
| AS8075 | Microsoft Corporation | 21 | 21 |
Where it comes from
| Country | Probes |
|---|---|
| United States | 172 |
| Belgium | 84 |
| Hong Kong | 66 |
| United Arab Emirates | 19 |
| China | 18 |
| Nigeria | 16 |
Client strings seen on this port
| User agent | Probes |
|---|---|
| visionheight.com/scan Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) Chrome/126.0.0.0 Safari/537.36 | 32 |
| Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36 | 28 |
| Hello from Palo Alto Networks, find out more about our scans in https://docs-cortex.paloaltonetworks.com/r/1/Cortex-Xpanse/Scanning-activity | 27 |
| Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36 Edg/120.0.0.0 | 20 |
| Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/153.0.0.0 Safari/537.36 | 12 |
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