coalg.org

.org crawl

First seen 2026-04-14 · Last seen 2026-05-17 · ok HTTP/1.1 200 91 ms crawled 2026-05-07

DE · 188.40.28.167 · AS24940 Hetzner Online GmbH

Reputation 87/100 weak security headers no dmarc policy

sector tech type docs

HTML metadata

Title: Coalgebra
Language: en
Generator: mkdocs-1.6.1, mkdocs-material-8.5.10
Canonical: https://coalg.org/

Technology

Server: Apache

Fonts

Google Fonts

Third-party hosts loaded (3)

cdnjs.cloudflare.com×3
fonts.googleapis.com×1
fonts.gstatic.com×1

Registration

Registrar

Key-Systems GmbH

Created

2011-05-11

Updated

2025-11-24

Name servers

ns.second-ns.com
ns1.your-server.de
ns3.second-ns.de

DNS records live

NS

ns.second-ns.com
ns1.your-server.de
ns3.second-ns.de

MX

10 www267.your-server.de

Email authentication weak

SPF: v=spf1 +a +mx ?all
neutral (?all)
DMARC: not published
DKIM: no key found at common selectors

Certificate (current)

R13

from 2026-04-01 to 2026-06-30

Expires in 42 days

Full certificate history on crt.sh ↗

HTTP security headers

Header hygiene 30/100 Checked live page: https://coalg.org/

findings

missing HSTS
missing Content Security Policy
missing frame protection
missing content type protection
missing Referrer Policy
missing Permissions Policy