Software Alternatives, Accelerators & Startups

Mailgun VS InboxStack

Compare Mailgun VS InboxStack and see what are their differences

Note: These products don't have any matching categories. If you think this is a mistake, please edit the details of one of the products and suggest appropriate categories.

Mailgun logo Mailgun

A set of powerful APIs that enable you to send, receive and track email from your app effortlessly whether you use Python, Ruby, PHP, C#, Node.js or Java.

InboxStack logo InboxStack

Email deliverability intelligence with root-cause AI
  • Mailgun Landing page
    Landing page //
    2023-07-16
  • InboxStack Dashboard
    Dashboard //
    2026-07-20
  • InboxStack Multi ESP Dashboard
    Multi ESP Dashboard //
    2026-07-20
  • InboxStack Multi Client View
    Multi Client View //
    2026-07-20

InboxStack is an email deliverability intelligence platform built for teams who need to know why their emails aren't reaching the inbox โ€” not just that they aren't. At its core is Brain, a proprietary causal AI engine trained on a 22-year deliverability knowledge base, which correlates signals across your ESP, DNS authentication records (SPF, DKIM, DMARC), Google Postmaster Tools, Microsoft SNDS, and 50+ blocklists to pinpoint root causes instead of surfacing raw metrics.

Most deliverability tools stop at monitoring: they show you a drop in inbox placement or a blocklist hit and leave you to investigate. InboxStack goes further, tracing the actual causal chain โ€” a DKIM misalignment, a reputation dip on a specific sending IP, a content trigger โ€” so you can fix the real problem instead of guessing.

Setup takes minutes with no migration required: forward your email headers for an instant DNS/authentication audit, or connect your existing ESP and Postmaster accounts for ongoing monitoring. Optional seed testing gives you real inbox-vs-spam placement data across major providers.

Built for agencies managing multiple client domains and growing companies who've outgrown basic authentication checkers, InboxStack turns deliverability from a black box into a diagnosable, fixable system.

InboxStack

$ Details
freemium $49.0 / Monthly
Platforms
Web
Release Date
2026 May
Startup details
Country
India
State
karnataka
City
Bengaluru
Employees
1 - 9

Mailgun features and specs

  • Scalability
    Mailgun can handle high volumes of emails efficiently, making it ideal for businesses of all sizes, from startups to large enterprises.
  • API Flexibility
    Mailgun offers a robust and flexible API that is developer-friendly, allowing for easy integration and customization to fit specific needs.
  • Deliverability
    Mailgun has strong email deliverability rates due to its reputation and infrastructure, which helps ensure emails reach recipients' inboxes as intended.
  • Analytics and Tracking
    It provides comprehensive email analytics and tracking features, allowing businesses to monitor open rates, click-through rates, and other vital statistics.
  • SMTP Relay
    Mailgun supports SMTP Relay, making it versatile for sending emails from a variety of applications and systems.
  • Support and Documentation
    Mailgun offers extensive support and documentation, which helps in troubleshooting and enhances the user experience.

Possible disadvantages of Mailgun

  • Cost
    Mailgun pricing can become expensive for high-volume email senders, especially when compared to some other email service providers.
  • Complex Setup
    Initial setup and configuration of Mailgun can be complex, particularly for users who are not very technical.
  • Spam and Bounce Management
    While deliverability is generally strong, some users have reported challenges with spam and bounce management, which can affect email performance metrics.
  • Learning Curve
    For those new to email APIs or less tech-savvy, there might be a steep learning curve to effectively use all of Mailgun's features.
  • Customer Support Response Time
    Some users have reported slower response times from customer support, which can be a drawback if immediate assistance is needed.

InboxStack features and specs

  • Inboxstack Brain
    Root-cause AI analysis (Brain)
  • Email Audit
    DNS/SPF/DKIM/DMARC authentication audit
  • DMARC Monitoring
    DMARC report monitoring
  • Deliverability Monitoring
    Google Postmaster, SNDS, Senderscore monitoring
  • Blacklist Monitoring
    50+ blocklist monitoring
  • Seed Testing
    Seed testing & inbox placement tracking
  • Warm-up
    Warmup plan and monitor
  • ESP Dashboard
    Multi ESP view dashboard

Analysis of Mailgun

Overall verdict

  • Mailgun is a solid choice for businesses looking for a dependable and scalable email service provider. Its feature-rich platform and ease of integration make it stand out in the industry.

Why this product is good

  • Mailgun is considered a reliable choice for email delivery due to its robust set of features tailored for transactional and marketing emails. It offers powerful APIs for easy integration, high deliverability rates, detailed analytics, and comprehensive logging. Its scalability meets the needs of both small startups and large enterprises. Mailgun also provides excellent support and documentation, making it accessible for developers.

Recommended for

  • Developers and tech startups requiring programmable email solutions
  • Companies seeking reliable transactional email services
  • Organizations looking for detailed analytics and reporting on email performance
  • Businesses requiring scalable solutions for sending both small and large volumes of emails
  • Users who need robust APIs for seamless email service integration

Mailgun videos

Introducing the new Mailgun

More videos:

  • Review - Why Emails are sent to Spam! Even with Premium Services Like Amazon SES, Sendgrid, Gsuite, Mailgun
  • Review - Getting Started with Mailgun

InboxStack videos

No InboxStack videos yet. You could help us improve this page by suggesting one.

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Category Popularity

0-100% (relative to Mailgun and InboxStack)
Email Marketing
100 100%
0% 0
Reputation Management
0 0%
100% 100
Email Marketing Platforms
Email
95 95%
5% 5

User comments

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Reviews

These are some of the external sources and on-site user reviews we've used to compare Mailgun and InboxStack

Mailgun Reviews

Transactional email providers for indie businesses 2020
Mailgunโ€™s one dedicated IP address starts with the Foundation plan ($35) for 100k emails and up ($75). You might consider going for the growth plan ($80) already with 1000 email address validations included.
10 Top Mailgun Alternatives | Most Affordable Competitors 2019
Mailgun SMTP is receiving 5 star reviews from people around the world. They are showering all the love, and support on Mailgun for their excellent service, features and usability.
Source: www.formget.com
The 36 Best Marketing Automation Tools to Use in 2020
Mailgun is an email infrastructure and transactional email platform built for developers that need a simple email API integration to send, receive, and track email with their app regardless of what programming language they use. Mailgun offers a flexible pricing model that starts at as low as $5/month for 10,000 emails.
Source: encharge.io
8 Most Reliable Mandrill Alternative SMTP Relays
Mailgun can push a webhook to the userโ€™s app ( like EasySendy Pro), whenever an action takes place on the sent emails. The MailGun API offers much more than just sending the emails. Users can send up to a thousand personalized email messages with a single API call, making it effortless to send out bulk mailings from an app. Moreover, users can use tags to segregate their...
Source: easysendy.com
7 Best Transactional Email Services: Sendgrid vs. Mandrill & More
Hi, I use Mailgun for sending transactional mails and send around 2k mails per week and we are on shared IP and so, I am facing some issues like ESP throttling issues, because of the others who are using the same as I do. I have to get my shared IP changed every time I ran into these kind of issues. Mailgun recommends to use a dedicated IP when you send more than 5k mails...

InboxStack Reviews

We have no reviews of InboxStack yet.
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Social recommendations and mentions

Based on our record, Mailgun seems to be more popular. It has been mentiond 11 times since March 2021. We are tracking product recommendations and mentions on various public social media platforms and blogs. They can help you identify which product is more popular and what people think of it.

Mailgun mentions (11)

  • The 7 best transactional email services for developers in 2023
    Mailgun from Sinch is a well-established, developer-focused email service that's been in business since 2010. It powers email delivery for some large, well-known companies including Lyft, American Express, and Wikipedia. As a developer-focused tool, Mailgun is fast to get started with and integrate into your product. It's an excellent offering if you're looking for a reliable, easy-to-use product. - Source: dev.to / almost 3 years ago
  • Mailgun REST API integration from serverless node.js
    In this Mailgun integration example we'll show how easy it is to create and deploy a complete serverless backend that integrates with the Mailgun SaaS API for sending email messages to your users. - Source: dev.to / over 3 years ago
  • Self-hosted email is the hardest it's ever been, but also the easiest
    Another solution to this problem is relaying through services which will do the heavy lifting for you (this was been discussed in the original thread, here and in the article I wrote). So far people have suggested - ImprovMX (https://improvmx.com) - Mailgun (https://mailgun.com) As any others come in I will update this comment (until I can't, anyway) and the article as a reference. - Source: Hacker News / almost 4 years ago
  • Anyone else getting bombarded with invoice spam emails? Iโ€™m using a custom domain. These have been relentless for months.
    Sure. I have an account with mailgun, though I have heard good things about sendgrid as well. It costs me $35/mo, but I use the account as part of the management of a phpbb forum I host, but I have a patreon for that that covers the expenses. If I didn't have that patreon, I would have to think pretty hard about how to proceed. Source: almost 4 years ago
  • SWBC wants to spoof emails in our domain to our customers, and wants us to add them to our SPF records
    As you can see, "mailgun.com" the "leading email delivery service for companies around the world" is included in their SPF despite not being them, precisely so they can spoof being Edward Jones, presumably in some marketing effort:. Source: about 4 years ago
View more

InboxStack mentions (0)

We have not tracked any mentions of InboxStack yet. Tracking of InboxStack recommendations started around Jul 2026.

What are some alternatives?

When comparing Mailgun and InboxStack, you can also consider the following products

MailChimp - MailChimp is the best way to design, send, and share email newsletters.

GlockApps - G-Lock Apps is an interesting tool that might seem simple to some, but is quite essential to most online marketers.

Twilio - Brings voice and messaging to your web and mobile applications.

Email Testing By Inbox Pirates - Preview, Analyze & Test emails with one click.

Brevo - Innovative online Email Marketing solution to manage your contacts, create & send your newsletters and track your results. More than 80 000 clients. Best prices and attractive features.

Validity LLC - Founded in 2010, located in Essex Countyโ€™s City of Orange, NJ, and serving all 50 states of the U.S., Validity, LLC is considered a โ€œOne Stop Shopโ€ for ...