What does StackOptic analyze?

StackOptic runs 18 analysis modules on any public website from a single URL. It detects 7,000+ technologies (CMS, frameworks, analytics, payments, CDN, hosting), evaluates SSL certificates and HTTP security headers with grades from A+ to F, measures Core Web Vitals (LCP, CLS, TBT, FCP), audits SEO meta tags and structured data, checks email security (SPF, DKIM, DMARC), analyzes AI & LLM readiness including bot access and llms.txt validation, extracts color palettes and typography, estimates carbon footprint, and generates permanent shareable reports.

Does it work on sites behind Cloudflare or bot protection?

Yes. StackOptic uses a real browser engine that loads pages exactly like a human visitor — executing JavaScript, rendering CSS, and handling redirects. This allows it to bypass Cloudflare, LiteSpeed, Sucuri, and other bot protection systems where traditional crawlers and HTTP-only tools fail.

What do I get on the free plan?

The free plan includes 5 analyses per day with access to all 18 modules, full scores, technology detection, and security grades. Every report is permanently accessible via a unique shareable URL — no login required to view. No credit card needed. AI-powered insights, re-analysis, PDF/JSON export, and comparison features are available on Pro ($24/mo) and Agency ($99/mo) plans.

What is AI & LLM readiness analysis?

This module evaluates how visible and citable your website is to AI search engines like ChatGPT, Perplexity, Google AI Overviews, and Claude. It audits access permissions for 8 major AI bots, validates llms.txt and llms-full.txt files, scores citation-ready content structure, and analyzes structured data (JSON-LD) for GEO readiness — helping you rank in the next generation of search.

How long does an analysis take?

Most analyses complete in under 10 seconds. StackOptic runs all 18 modules in parallel using a real browser session, so you get technology detection, security audit, performance metrics, SEO analysis, and AI readiness scoring simultaneously.

How accurate are the results?

Detection is based on real browser execution — DOM inspection, JavaScript runtime analysis, HTTP headers, and DNS records. With 7,000+ technology signatures and Lighthouse-calibrated performance scoring, StackOptic achieves high accuracy for mainstream technologies.

What security checks are performed?

The security module evaluates SSL/TLS certificates, 12+ HTTP security headers (HSTS, CSP, X-Frame-Options, Permissions-Policy, Referrer-Policy), HTTPS enforcement, and email authentication (SPF, DKIM, DMARC). Each site receives a letter grade from A+ to F with specific remediation steps.

Do you store the websites I analyze?

StackOptic only stores publicly available information that any visitor to a website would see — HTML content, HTTP headers, DNS records, and screenshots. We do not access private data, log in to websites, or perform any intrusive testing.

Back to Search

smtp2go.com

https://smtp2go.com· First analyzed 19 Feb 2026· Updated 19 Feb 2026

Export

smtp2go.com

Sponsored

Hosting Provider

Smtp2go Coresite3

IP Address

43.228.184.5

Server Location

🇺🇸 Chicago, United States

ASN

AS1299

Organization

Smtp2go Coresite3

Server

Cloudflare

CDN

Cloudflare

WAF

Cloudflare

Nameservers

sns4.treshna.co.nz.sns3.treshna.co.nz.ns2.smtpcorp.com.ns4.smtpcorp.com.

Performance

Page Speed

2.2 MB

64 requests

Image Optimization

Lazy LoadWebP

0–49

50–89

90–100

Architecture Stack

Monolithic

⚙️ SSR

Frontend

Framework

jQuery

Styling

Bootstrap

CMS

WordPress

Infrastructure

Hosting

Smtp2go Coresite3

CDN

Cloudflare

Technology Stack

11 Technologies Detected

Plugins

CSS Frameworks

Libraries

Analytics

Tag Managers

Customer Support

Reviews

CDN

SEO Analysis

A82/100

smtp2go.comsmtp2go.com

SMTP2GO: Reliable & Scalable Email Delivery Service

SMTP2GO is the scalable, reliable email deliverability solution. Worldwide servers, a robust API, and powerful reporting set us apart. Try our free plan!

Title Length51 chars

Recommended: 50-60 chars

Description Length153 chars

Recommended: 120-160 chars

Issues (0)

2 issues found

Upgrade to view details

Crawlability

Sitemap

Type: standard

robots.txt

3 rules

Sitemap reference found

Sponsored

Security Score

0%Critical

Critical / Transactional

HTTPS

WAF

119d

Certificate Details

Type

Domain Validated (DV)

Certificate Authority

Sectigo Limited

Key Algorithm

RSA (2048 bit)

Signature

SHA-256 with RSA

TLS Version

TLSv1.3

HTTP Protocol

HTTP/2+H3

Valid From

18.05.2025

Valid Until

18.06.2026

OCSP Stapling

Enabled

Subject Alternative Names (2)

*.smtp2go.comsmtp2go.com

SHA-256 Fingerprint

18:17:E1:E6:DA:BE:16:3A:15:CD:AC:9B:C9:07:41:C1:6C:34:86:9B...

Top Recommendations

Security recommendation preview

Upgrade to view recommendations

Upgrade to view header details

HTTP Headers

Developer Console

access-control-allow-origin

http://www.smtp2go.com/

alt-svc

h3=":443"; ma=86400

cache-control

🟡 600s(max-age=600, must-revalidate)

cf-cache-status

DYNAMIC

cf-ray🇩🇪 Frankfurt

9d061494bf39dc95-FRA

content-encoding

⚡ Brotli(br)

Good Warning Issue

Email Infrastructure

Google Workspace

Score

100

SPF

DKIM

DMARC

DMARC Policy

Reject (Strictest)

MX Records (5)

aspmx.l.google.com

alt1.aspmx.l.google.com

alt2.aspmx.l.google.com

alt3.aspmx.l.google.com

+1 more

Domain Information

smtp2go.com

Domain Age

19y 8m

Created

20.06.2006

Expires

20.06.2028

Last Updated

11.06.2025

Registrar

GoDaddy.com, LLC

DNSSEC

Not Enabled

Privacy & Compliance

OneTrust

Cookie Consent Banner

OneTrust

GDPR Indicators

Cookie consent banner detected

CMP: OneTrust

Typography & Readability

Open Sans

63/100

Readability

/30

20/40

13px · LH 1.50

Hierarchy

/20

25/25

2.77x ratio

WCAG

/25

15/15

Contrast: undefined

Performance

/25

13/20

1 font

Heading Font

Open Sans

Sans36px

Body Font

Open Sans

Sans13px

Contrast Ratio

Reading Comfort

~42 CPL

Needs attention

36px

28px

17px

13px

❌ Critical: 13px body text is too small. Increase to at least 14px.

✅ Optimal line spacing: 1.50 ratio ensures comfortable reading.

✅ Strong hierarchy: Headlines are 2.8x larger than body text.

✅ Good performance: Using 1 font families keeps load times fast.

✅ Consistent design: Single font family with weight variations is a modern best practice.

✅ Smart font loading: Using font-display: swap prevents invisible text during load.

Buy on MyFonts

Business & Marketing Stack

8 Tools Detected

Enterprise

Behavior Analytics

Google Tag ManagerFree

HotjarMid-Market

Matomo (Piwik)Mid-Market

KissmetricsMid-Market

Google AnalyticsFree

User behavior and product analytics

Advertising

Reddit PixelMid-Market

Ad platforms and retargeting pixels

A/B Testing & Optimization

ConvertMid-Market

Experimentation and conversion optimization

Reviews & Social Proof

TrustpilotMid-Market

Customer reviews and testimonials

Sponsored

Scripts & Styles

21 Resources

Scripts

Styles

Async

Defer

Top Script Sources

smtp2go.com(11)code.jquery.com(2)redditstatic.com(1)cdn-au.onetrust.com(1)gstatic.com(1)

Website Identity

Facebook X (Twitter)Instagram LinkedIn

Sponsored

Last analyzed: 19 Feb 2026 at 13:23

Historical Analysis & Change Tracking