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https://zimbra.com

Infrastructure

· 9 checks — DNS, redirects, IPv6, crawlability, URL variants, and domain intelligence rolled into one auditable list.
SCORE
83
GRADE
B
FIX
0
REVIEW
3
PASS
6
INFO
0
Probed from Singapore, Singapore
301 Moved Permanently
Checks
9
6 PASS 3 REVIEW
C
Crawlability
Action
robots.txt present, sitemap with 4 URLs
REVIEW
robots.txt present, sitemap with 4 URLs
Info::
robots.txt is present
Got: 860 bytes
Critical::
robots.txt blocks all crawlers
Disallow: / for all user-agents prevents search engines from indexing any page. This will remove the site from search results.
Info::
sitemap.xml is present
Info::
sitemap.xml is valid XML
Info::
sitemap.xml contains 4 entries
Info::
Sitemap index with 4 child sitemaps
Info::
robots.txt references sitemap

Disallow: / for all user-agents prevents search engines from indexing any page. This will remove the site from search results.

Why this matters

Disallow: / in robots.txt blocks every search crawler — the site becomes invisible in organic search.

Learn more

Common deployment mistake: a staging robots.txt with `User-agent: * / Disallow: /` ships to prod. The site falls out of search results within days. Verify your robots.txt is the production-intended version. If this is intentional (private site), no action needed.

Source: Google Search Central

robots.txt 200 OK
Size 860 B Sitemaps referenced 1 User-agents Googlebot-Mobile, MSNBot-media, AdsBot-Google, Mediapartners-Google, Rogerbot, PowerMapper, Netcraft, Googlebot-News, AdsBots-Google-Mobile, slurp, Googlebot-image, Googlebot-Video, *, bingbot, Googlebot, MSNBot Blocking Yes — all crawlers blocked
# Deny all robots that we do not specifically want to allow
User-agent: *
Disallow: /

# Allow these robots only
User-agent: slurp
Allow: /

User-agent: bingbot
Allow: /

User-Agent: Googlebot
Allow: /

User-agent: Googlebot-image
Allow: /

User-agent: MSNBot-media
Allow: /

User-agent: MSNBot
Allow: /

User-agent: Netcraft
Allow: /

User-agent: Googlebot-Mobile
Allow: /

User-agent: AdsBot-Google
Allow: /

User-agent: Googlebot-Video
Allow: /

User-agent: Googlebot-News
Allow: /

User-agent: Mediapartners-Google
Allow: /

User-agent: AdsBots-Google-Mobile
Allow: /

User-agent: Rogerbot
Allow: /

User-agent: PowerMapper
Allow: /

Disallow: /feed/
Disallow: /trackback/
Disallow: /wp-admin/
Disallow: /wp-content/
Disallow: /wp-includes/
Disallow: /xmlrpc.php
Disallow: /wp-
Allow: /wp-content/uploads/
Sitemap: https://www.zimbra.com/sitemap_index.xml

B
URL Variants
www/non-www, trailing slash, HTTP→HTTPS
REVIEW
www/non-www, trailing slash, HTTP→HTTPS
Critical::
Both www and non-www versions serve content
Got: Both variants return 200 Expected: One variant 301-redirects to the other
Info::
HTTP correctly 301-redirects to HTTPS

www / non-www

200https://www.zimbra.com/
200https://zimbra.com/

Inconsistent — duplicate content risk

HTTP → HTTPS

301http://zimbra.com/ https://zimbra.com/

Consistent

B
TLS Certificate Expiry & Recommendations
63 days until leaf cert expires — 5 issues to address
REVIEW

Certificate validity

63
days left
0d 30d 60d 90d+

Recommended actions

  • Extend HSTS max-age to at least 31536000 (1 year) to meet the preload list criteria
  • Add includeSubDomains to the HSTS directive
  • Add the preload directive and submit to hstspreload.org once max-age + includeSubDomains are in place
  • Enable DNSSEC on your domain for DNS spoofing protection
  • Enable OCSP stapling on your TLS server to remove a CA roundtrip and protect user privacy
A
DNS Records
1 A records, 205 ms lookup
PASS
1 A records, 205 ms lookup
Info::
Resolves to 1 IPv4 address(es)
Got: 23.185.0.2
Info::
Single A record — no DNS redundancy
Multiple A records provide failover if one server goes down.
Info::
Has 2 IPv6 (AAAA) record(s)
Got: 2620:12a:8000::2, 2620:12a:8001::2
Info::
4 nameserver(s) configured
Got: dns1.p05.nsone.net, dns2.p05.nsone.net, dns3.p05.nsone.net, dns4.p05.nsone.net
Info::
3 mail exchanger(s) configured
Info::
CAA records not checked
CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.
Info::
SPF record present in TXT
Warning::
DNS resolution is slow (205 ms)
Slow DNS adds latency to every page load. Consider a faster DNS provider.
Got: 205 ms
A23.185.0.2
AAAA2620:12a:8000::2, 2620:12a:8001::2
CNAME
NSdns1.p05.nsone.net, dns2.p05.nsone.net, dns3.p05.nsone.net, dns4.p05.nsone.net
MX
0 mail.zimbra.com
10 mta03.zcom.email-ash1.synacor.com
10 mta04.zcom.email-ash1.synacor.com
TXT
SPF v=spf1 ptr mx ip4:52.7.157.95 ip4:52.70.125.224 ip4:52.204.246.185 ip4:52.205.85...
cisco-ci-domain-verification=681f562fa07c58c993c8bfde487542cb70b5b5eef7753e423d2...
CAALookup not available with standard resolver
Resolved in 205 ms

Multiple A records provide failover if one server goes down.

Why this matters

Single A record means a single point of failure — if that IP goes down, your site is unreachable until DNS TTL expires.

Learn more

Add multiple A records for round-robin failover, or use a managed DNS provider with health-checked failover (Route 53, Cloudflare, NS1). Short TTL (60-300s) lets clients recover faster on outages.

Source: SRE practice / DNS architecture

CAA record lookup requires a specialized DNS resolver. This check will be available in a future update.

Why this matters

Informational: CAA (Certification Authority Authorization) records weren't checked in this scan.

Slow DNS adds latency to every page load. Consider a faster DNS provider.

Why this matters

DNS resolution is slow — anycast DNS providers (Cloudflare, Route 53) typically resolve <50ms globally.

Source: DNS performance benchmarks

A
Redirect Chain
1 redirect(s), 22 ms total
PASS
1 redirect(s), 22 ms total
Info::
Single redirect
Got: https://zimbra.com → https://www.zimbra.com/ (301)
Info::
WWW normalization redirect

https://zimbra.com

10 ms · HTTP/1.1

301

https://www.zimbra.com/

11 ms · HTTP/1.1 FINAL

#URLStatusTimeProtocolServer
1https://zimbra.com30110 msHTTP/1.1nginx
2https://www.zimbra.com/20011 msHTTP/1.1nginx

See the visual redirect chain in the HTTP Probe tab →

A+
IPv6 Readiness
IPv6 reachable (1 ms)
PASS
IPv6 reachable (1 ms)
Info::
IPv6 is configured and reachable at 2620:12a:8000::2, 2620:12a:8001::2
Got: 1 ms connect
IPv6 Ready
AAAA Records 2620:12a:8000::2, 2620:12a:8001::2 Connection Reachable (1 ms)
A
Domain Intelligence
zimbra.com — via CSC Corporate Domains, Inc., 25 years, 3 months old
PASS
zimbra.com — via CSC Corporate Domains, Inc., 25 years, 3 months old
Warning::
Domain expires in 40 days
Consider enabling auto-renewal to prevent accidental expiration.
Got: Expires Jun 1, 2026
Info::
DNSSEC is not enabled
DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.
Info::
Registrar: CSC Corporate Domains, Inc.
Warning::
Registrar lock is NOT enabled
The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.
Domain expiry

EXPIRED

June 1, 2026

SSL certificate

63 days

Issued by Let's Encrypt

Domain age

25 years, 3 months

Registered June 1, 2001

DNSSEC

Not enabled

Protects against DNS spoofing

Hosting

Unknown

2620:12a:8000::2

Registrar

CSC Corporate Domains, Inc.

Unlocked 4 NS records
Expiry timeline
Today
+1 year
Domain expiry SSL expiry Danger zone (≤30 days)
Recommended actions
  • Domain has EXPIRED — renew immediately to avoid total site outage
  • Enable DNSSEC to protect visitors from DNS spoofing
  • Enable registrar lock (clientTransferProhibited) to block unauthorized domain transfers
Registrar CSC Corporate Domains, Inc.
Created June 1, 2001 (25 years, 3 months ago)
Expires June 1, 2026 (1 months)
Last Updated May 28, 2025
Name Servers dns1.p03.nsone.net, dns2.p03.nsone.net, dns3.p03.nsone.net, dns4.p03.nsone.net
DNSSEC Not enabled
Hosting
IP Address 2620:12a:8000::2
Data source: rdap (0.0s)

Consider enabling auto-renewal to prevent accidental expiration.

Why this matters

Domain expiry approaching — renew immediately and ensure auto-renew + alerting are configured.

Source: ICANN renewal policy

DNSSEC protects against DNS spoofing attacks. While not required, enabling DNSSEC adds an additional layer of security. Contact your DNS provider to enable it.

Why this matters

Without DNSSEC, an attacker who can poison your DNS can hijack your domain — and SSL certs alone don't stop them.

Learn more

DNSSEC adds cryptographic signatures to DNS records, preventing forged responses from poisoning resolver caches. Without it, an attacker who controls the network path can redirect your domain to a malicious server before any HTTPS handshake happens. Most modern registrars (Cloudflare, Google Domains, Route 53) enable it with one toggle.

Source: ICANN / RFC 4033

The domain can be transferred without an unlock step. Enable registrar lock (clientTransferProhibited) in your registrar's control panel to protect against unauthorized or accidental transfers.

Why this matters

Without registrar lock, an attacker who phishes your registrar credentials can transfer the domain in minutes — total brand hijack.

Learn more

Registrar lock (clientTransferProhibited, clientUpdateProhibited, clientDeleteProhibited) requires extra verification before any transfer/update/delete. Every major registrar offers it free. Combined with 2FA on your registrar account, it's the strongest defense against domain hijacking.

Source: ICANN / domain-security best practice

A+
HTTP Probe Timing
Total 15 ms — DNS, TCP, TLS, TTFB, content transfer breakdown
PASS
DNS Lookup DNS Lookup — time to resolve the domain name to an IP address.
7 ms
TCP Connect TCP Connect — time to establish a TCP connection to the server.
1 ms
TLS Handshake TLS Handshake — time to complete the HTTPS encryption handshake.
4 ms
Time to First Byte Time to First Byte — how long the server takes to respond with the first byte of data.
15 ms
Total Time Total request time from DNS lookup through full response.
15 ms

Connection waterfall

DNS Lookup 7 ms TCP Connect 1 ms TLS Handshake 4 ms Server Processing 3 ms Content Transfer 0 ms
A+
CDN & Delivery
Fastly (HIT, HIT)
PASS
Fastly (HIT, HIT)
Info::
Site is served via Fastly CDN
Got: x-served-by: cache-chi-klot8100079-CHI, cache-sin-wsat1880060-SIN
Info::
CDN cache status: HIT, HIT
CDN Detected: Fastly
Provider Fastly Cache Status HIT, HIT Evidence x-served-by: cache-chi-klot8100079-CHI, cache-sin-wsat1880060-SIN
All checks on this page are automated. Results are estimates - run targeted manual reviews when the score affects a release decision.

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