Email on Acid

What Email on Acid does

Email on Acid, founded in 2009 and headquartered in San Antonio, Texas, is a Software-as-a-Service platform that provides pre-deployment email testing, troubleshooting, and quality assurance tools for email marketers and front-end developers. The platform tests HTML emails across more than 100 email clients, devices, and inbox providers before campaigns are sent, supplemented by modules for accessibility testing (aligned with WCAG 2.2 and the European Accessibility Act), spam content analysis, link and image validation, HTML code analysis, and inbox display previews. Deliveries are guaranteed in under 10 seconds with 99.9% platform uptime, and the platform maintains ISO 27001, ISO 27701, SOC 2 Type II, and GDPR compliance certifications.

The company operates a tiered subscription pricing model with a Basic plan at $99/month (1,000 previews), a Premium plan at $199/month (2,000 previews plus the full QA suite), and custom-priced enterprise contracts for large teams. Distribution is hybrid: self-serve product-led growth through direct website sign-up for SMB and individual developers, a dedicated enterprise sales motion with custom demo and white-label embedding via API for larger organizations and SaaS partners, and inclusion in the Mailgun ecosystem. Email on Acid became a wholly-owned subsidiary of Sinch AB (Nasdaq Stockholm) in 2021 alongside Mailgun and Mailjet, and is currently transitioning into Mailgun Inspect — a next-generation email QA suite built on the Mailgun platform — with customer migration scheduled to begin June 2026. Named enterprise customers include Hilton, IBM, Bang & Olufsen, Forrester, KLM, The New York Times, AECOM, Bloomberg BNA, Omni Hotels, and Level-Ex.

Name

Email on Acid

Legal name

Email on Acid, LLC

Website

https://emailonacid.com

Company type

Private

Founded year

2009

Operating status

Operating

Headcount range

11–50 employees

Short description

Email on Acid is a SaaS platform providing pre-deployment email QA and rendering testing across 100+ clients and devices, serving email marketers, developers, and enterprises globally as part of Sinch Email.

Ownership category

akta.pro rank

Product category

Email Quality Assurance Software

NAICS

Software Publishers (5132), Computer Systems Design and Related Services (54151), Custom Computer Programming Services (541511)

SIC

Services-Prepackaged Software (7372), Services-Computer Programming, Data Processing, Etc. (7370), Services-Computer Programming Services (7371)

akta.pro primary industry

Email Marketing Services (Campaigns, Deliverability, Lifecycle) (BPAFAKAB)

akta.pro secondary industries

Email Marketing Services (Campaign Strategy, Design, Deliverability) (MPAAAIAA), Webhooks, Eventing & Message Streaming (BPAMAOAE)

Keywords

• Email preview testing
• Email quality assurance
• Email accessibility testing
• Email deliverability analysis
• Email rendering verification

Headquarters

HQ city

Greenwood Village

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Personnel, Marketing or Sales, Infrastructure, Operations

Revenue model

1. SaaS Subscription - Basic Tier: Monthly subscription at $99 per month providing 1,000 email previews per month, 100+ email preview clients and devices, unlimited users, and API access. Overages charged at $0.15 per preview.
2. SaaS Subscription - Premium Tier: Monthly subscription at $199 per month providing 2,000 previews per month, accessibility tests, HTML code analysis, link and image validation, and spam content checks.
3. Enterprise Custom Contract: Custom contract pricing for enterprise customers with tailored preview allotments and enterprise-level features. Negotiated pricing through sales team.

Pricing tiers

Go-to-market motion2 records

Distribution channels4 records

Marketing channels10 records

Core offering

Email on Acid provides a SaaS-based email pre-send quality assurance (QA) and preview testing platform that allows marketers and developers to test HTML emails across 100+ email clients and devices before sending. The offering includes email previews, accessibility testing against WCAG 2.2, link and image validation, HTML code analysis, spam content analysis independent of sender reputation, and white-label/OEM embedding capabilities for partner platforms. The platform is offered via tiered SaaS subscriptions (Basic $99/month, Premium $199/month), enterprise custom contracts, and is being succeeded by Mailgun Inspect as part of the Sinch Email ecosystem.

Product overview

Email on Acid, now operating as part of Sinch Email alongside Mailgun and Mailjet, offers Mailgun Inspect as its primary next-generation email quality assurance platform. The core product provides email preview testing across 100+ clients and devices, supplemented by individual modules for email accessibility, image validation, link validation, HTML code analysis, inbox display, campaign precheck, and spam content analysis. Enterprise Solutions offer customized workflows for large teams, while White Label Previews allow partners to embed the preview technology into their own platforms. The platform operates on a tiered pricing model (Basic at $99/mo with 1,000 previews, Premium at $199/mo with 2,000 previews) with API access available across plans.

Differentiator

Problem solved

Functional benefit

Brands

• Mailgun Inspect: The next-generation email quality assurance platform that succeeds Email on Acid, fully integrated into the Mailgun platform. Built on the Mailgun platform, it manages the full email lifecycle from pre-send checks to high volume delivery to post-send analysis.

Products and services

• Mailgun Inspect Next-generation email quality assurance platform succeeding Email on Acid, built on the Mailgun platform under the Sinch Email ecosystem. Provides pre-send preview testing across 100+ email clients and devices, accessibility (WCAG 2.2), image validation, link validation, HTML code analysis, and spam content checks, integrated with high-volume delivery and post-send analysis.
• Email on Acid Platform The Email on Acid SaaS platform that previews and validates HTML emails across 100+ email clients and devices before sending. Available via Basic ($99/month) and Premium ($199/month) subscriptions and custom enterprise contracts, with REST API access and overage-based usage pricing.
• Enterprise Solutions Customized email QA offering for large organizations with dedicated email marketing teams. Provides simplified QA workflows, flexible platform configuration to fit any team process, and custom preview allotments negotiated under multi-year enterprise contracts with dedicated sales support.
• White Label Previews White-label/OEM offering that integrates Email on Acid's email preview technology into partner apps, SaaS platforms, and ESPs under their own brand via REST API, allowing partners to deliver customer-facing email QA capabilities without building the underlying rendering infrastructure.

Quantifiable outcome

• Previews delivered in under 10 seconds
• +3 more outcomes

Named customers10 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

Yes

API docs

API detail

Core technology

AI maturity

App detail

Feature10 records

Partnerships

One partnership is on record.

• SinchcoreOthers · 1 January 2021Sinch acquired Email on Acid (along with Mailgun and Mailjet) in 2021, bringing all three brands under the Sinch Email umbrella. Sinch is a global cloud communications platform. Email on Acid operates as a product within Sinch Email's suite of email solutions.

Scale indicators4 records

Recent moves7 records

Expansion highlights6 records

Direct peers

• Litmus: Litmus is the most well-known direct competitor — an email pre-send testing and QA platform offering previews, spam testing, and analytics. It addresses the same email marketer and developer persona with a comparable subscription model.
• Mailtrap: Mailtrap provides email testing sandboxes and pre-deployment QA used by developers. Sister product within Sinch Email, addressing very similar pre-send QA and rendering pain points for the same email-developer persona.

Broad incumbents

• Validity (ReturnPath): Validity, including the ReturnPath heritage, operates a large email deliverability and data platform (Everest) used by major senders. It overlaps with Email on Acid in deliverability and inbox-rendering analytics but sits inside a much broader data/CRM suite.
• Mailgun / Sinch Email: Mailgun is the sibling email-sending platform that now houses Mailgun Inspect (the successor brand). It broadens the offering into full email lifecycle — sending, deliverability, QA — and is the natural upsell channel for Email on Acid customers.
• Twilio SendGrid: Twilio SendGrid is a major ESP that bundles email sending with some delivery and rendering analytics. It overlaps as an incumbent where customers consolidate QA into a single sending vendor.
• Klaviyo: Klaviyo is a leading B2C CRM/ESP used by ecommerce brands, the same persona Email on Acid targets for QA. Klaviyo increasingly bundles previews and inbox rendering features, partly substituting for standalone tools.
• HubSpot Marketing Hub: HubSpot Marketing Hub is a broad marketing automation platform used by enterprise email marketers (already including Hilton, and overlapping with Email on Acid's installed base). It competes for marketing-team QA budget via bundled testing capabilities.

Emerging players

• GlockApps: GlockApps is a niche email deliverability and spam-testing tool that competes in the same inbox-placement and content-spam analysis adjacent to Email on Acid's content spam checks.
• InboxPros: InboxPros is an email deliverability consultancy and monitoring service that overlaps with Email on Acid's spam content analysis and inbox placement testing use cases for mid-market senders.
• Folderly: Folderly offers email deliverability monitoring and content testing tools focused on spam placement and authentication. It targets a similar email-marketer persona with a more automation-driven positioning.

Market position

Strengths4 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xx.com/emailonacid
• Facebookfacebook.com/EmailonAcid
• LinkedInlinkedin.com/company/email-on-acid

Compliance5 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Email on Acid