Another fine day, the user's password reset email goes straight to spam, and your support team calls out the developer's name again. Have you ever had a headache choosing between SendGrid and Mailgun, the two "big guys" in the automatic email sending industry? I used to. After dozens of projects struggling with APIs, webhooks and a bunch of red logs, I decided to write an article analyzing transactional email SendGrid vs Mailgun right in the context of 2026. Let's dissect who you should shake hands with so that your transaction email is not only sent, but also sure to land safely in your inbox.
SendGrid vs. Mailgun 2026: Who is the "true love" for Vietnamese developers?
Both SendGrid and Mailgun are leading cloud platforms, but SendGrid is more of a comprehensive solution for both marketing and transactions, while Mailgun is laser-focused on developer experience with a powerful API.
Comparing SendGrid and Mailgun is always a hot topic on technology forums. At Pham Hai, we realize that each platform has its own design philosophy and customer file. A review of SendGrid (now part of the Twilio SendGrid ecosystem) shows that it is an extremely versatile tool. It not only provides a powerful email sending infrastructure for coders, but also has an intuitive and friendly user interface (UI/UX) for marketing teams.
In contrast, the Mailgun (now Sinch Mailgun) review paints a much more technical picture. This platform was born to optimize the developer experience, smoothly handling complex backend data streams. The SendGrid vs Mailgun battle for programmers is essentially a trade-off between "all-in-one" convenience and in-depth system control.
Quick comparison table: SendGrid and Mailgun put on the scale
The table below quickly summarizes the core criteria such as features, target audience, and strengths and weaknesses of the two platforms based on the latest updates in 2026.
For you to easily visualize before going into details, I have summarized the SendGrid feature and Mailgun feature through the following quick comparison table:
| Criteria | Twilio SendGrid | Born Mailgun |
|---|---|---|
| Định hướng cốt lõi | Transactional Email & Email Marketing | Pure API & Transactional Email |
| Inbound Parsing | Basic support | Extremely Powerful (Flexible Routing) |
| Phù hợp nhất cho | Startups and businesses need All-in-one | Developer, The system has complex logic |
Looking at the table above, SendGrid's advantages and disadvantages lie in its versatility. You can do everything, but sometimes the system is a bit cumbersome if you just need a simple API to send an OTP code. Meanwhile, Mailgun's pros and cons are its almost unmatched inbound email processing power on the market, but in return, it lacks intuitive drag-and-drop design tools for non-tech users.
Price: The never-ending war and the "shock" Mailgun is no longer free
In 2026, Mailgun has limited the free package to only 100 emails/day, equivalent to the current SendGrid level, making upgrade costs a big problem for startups.
The cost of sending transactional emails is always a vital factor when scaling a project. In the past, developers really liked Mailgun because of its generous free package of up to 10,000 emails/month. But the sad news is that the "shock" that Mailgun is no longer completely free has come true. So currently, how many emails does Mailgun free? Only 100 emails/day, mainly used for API testing purposes. If you want to put it into production, Mailgun prices start at $15/month for the Basic package (10,000 emails) and jump to $35/month for the Foundation package (50,000 emails).
So what about SendGrid pricing? How many emails does SendGrid free? They also apply a permanent limit of 100 emails/day (after the 60-day trial of premium features expires). However, the cost of SendGrid's email service is somewhat "softer" in the mid-range segment. Their API Essentials plan starts at $19.95/month for 50,000 emails. Clearly, when compared at the 50k email mark, SendGrid is offering a price advantage. However, keep in mind that the free packages of both are now just "ride on horseback to see flowers".
Deliverability: Who is more trustworthy when sending large amounts of email?
Mailgun is slightly better in terms of pure inbox ratio for transactional emails thanks to strict IP management, while SendGrid sometimes has trouble with Shared IP on its cheap plans.
Deliverability (the ability to deliver successfully to the inbox) is the "soul" of every email system. SendGrid's reliability has been proven through billions of emails sent every day to big companies. However, in cheap packages that use Shared IP (shared IP), if a "neighbor" in the same IP range sends spam, your email is also at risk of being implicated and falling into the Spam folder. To completely solve it, you must upgrade to the Pro package (about $89.95/month) to own a Dedicated IP (exclusive IP).
On the other hand, Mailgun's reliability is highly appreciated by engineers thanks to its smart threading infrastructure. Their email delivery speed is almost instantaneous. Even if you use Mailgun's Shared IP, the Bounce rate (return rate) is still strictly monitored and controlled by the system. To optimize this process, equipping yourself with knowledge about Email deliverability increases inbox rate is an indispensable tool to help you protect your business's email reputation.
API & Developer Experience: Which platform is more "friendly" to programmers?
Mailgun provides excellent RESTful API and SDK documentation, specifically designed for developers, surpassing SendGrid in its ability to handle complex Inbound Routing.
Developer experience is the battlefield that clearly determines victory and defeat. The SendGrid API is very well built, clearly documented, and supports a wide variety of programming languages. The ability to integrate SendGrid Mailgun into modern frameworks such as Node.js, Python, Ruby or PHP can all be done through official SDKs with just a few dozen lines of code.
However, the Mailgun API is truly the "true love" of hardcore coders. Mailgun's RESTful API architecture allows you to intervene deeply into each request. Mailgun's biggest selling point is its Inbound Routing feature (analyzing received email flow). It can automatically read a customer email reply, extract text, attachments and shoot straight into your database via JSON format. SendGrid also has Inbound Parse but the configuration is often more complicated and less flexible.
Outstanding features: Webhooks, Logs, and Email Validation - small but powerful things
Mailgun's Webhooks and Logs provide more detailed debug information for the backend, while SendGrid has a powerful built-in Email Validation tool that helps clean recipient lists.
When the system reports an error, you need to know exactly which step the email "died" at. Mailgun email log allows storing details from 5 to 30 days (depending on package), transparently displaying each event such as Accepted, Delivered, Opened or Bounced. SendGrid email log also provides similar data, but the search interface sometimes responds a bit slowly if the amount of lookup data is too large.
Regarding Webhook Mailgun and Webhook SendGrid, both platforms allow real-time notifications to be sent to your server when a user opens an email or clicks on a link. This is extremely useful for analyzing email performance and running A/B testing campaigns. In addition, the SendGrid email validation feature helps eliminate fake email addresses before sending, protecting IP reputation. Mailgun email authentication is also great, but this feature usually requires you to pay extra or use premium plans. Overall, both customer care services are professional, but SendGrid seems to be better in terms of response speed via live chat on paid plans.
What is Transactional Email that is so important?
Transactional email is an automatic email that is activated by the system and sent to a specific individual based on their actions or transactions on the website/application.
To choose the right tool, we must first understand what transactional email is. Unlike sending a handwritten letter to a series of people, a transactional email is a one-to-one response from the system. When the user clicks the "Register account" button, the system immediately activates the code via the email API to send a welcome email containing the activation link. The best transactional email sending platform is one that ensures a delivery delay of just milliseconds, because no customer wants to have to wait 10 minutes to receive an OTP code for payment.
Don't get confused: The core difference between transactional email and marketing email
Transactional emails are automatically triggered by user actions (such as purchases, password changes), while marketing emails are sent in bulk according to the business's purpose for promotion.
Many people who are new to the system often combine these two concepts into one. The difference between transactional email and email marketing lies in the core purpose and sending mechanism. Email marketing is about managing large-scale email lists, using beautifully designed email templates for the purpose of closing sales or nurturing leads. To understand how to implement these promotional campaigns, you can refer to the article Email marketing guide for beginners.
In contrast, transactional email automation is only concerned with conveying essential, highly personalized information. A small but vital note: you absolutely should not use the same IP address or domain for both types of email to avoid the risk of losing the domain's reputation. If you are curious about the underlying reason, the analysis article Transactional email vs email marketing will give you detailed answers.
Transactional email examples you encounter every day: From order confirmations to forgotten passwords
The most common examples include password reset emails, electronic purchase invoices, privacy policy change notifications, and confirmation of successful account creation.
You may not notice, but you interact with these systems every day. The most typical transactional email example is when you order food on an application, immediately there is an email saying "Your order #123 is being prepared by the restaurant". Or when you log into your bank account from an unfamiliar device, an urgent security alert will go straight to your inbox. Setting up automatic transactional email sending not only helps maintain peace of mind and transparency with customers, but also significantly reduces the workload for the operations department.
"Hardcore" experience: Integrate and operate SendGrid/Mailgun properly?
To operate the system stably, you need to choose a service with good scalability, fully set up DNS security records, and continuously monitor the status via a webhook/log system.
Choosing a transactional email service is not just about looking at the price list, but you must consider scalability and long-term system reliability. At Pham Hai, with experience supporting many partners, we have witnessed many businesses having to "destroy and rebuild" the entire email sending flow just because they initially chose the wrong platform. Email security and inbox rate are two factors you must configure correctly from the first day (Day 1) of starting to code.
Choosing the golden sending side: Should startups use SendGrid or Mailgun?
Startups that need a flexible, economical solution and have available marketing tools should prioritize SendGrid, while technology projects heavy on backend data processing should choose Mailgun.
The question of SendGrid vs Mailgun for startups is always a headache for Founders and CTOs. According to my real-life experience, if your team has a small number of people and wants to send stable OTP codes and occasionally send emails announcing new feature launches to users, SendGrid is an extremely safe choice. It serves as an "all in one" solution.
However, the market in 2026 does not only have these two names. Other "big guys" such as Postmark (king of sending speed), Amazon SES (super cheap cost for people familiar with AWS) or Brevo platform are also very formidable. If you're wondering more about powerful marketing support tools, the Mailchimp vs ConvertKit vs Brevo comparison review will provide more interesting perspectives for you to consider.
Required configuration to avoid spam: What are SPF, DKIM, DMARC and how to install?
SPF, DKIM, and DMARC are three DNS authentication standards that must be configured to prove to mailbox providers (like Gmail, Outlook) that you are a legitimate sender.
Even if you spend money to buy the best Dedicated IP package but forget to configure DNS, the email will still "land" in the trash as usual. The first is the SPF record, which acts like a protection list, publicly declaring which IPs (for example SendGrid or Mailgun's IP) are allowed to send mail on behalf of your domain. Next is DKIM, a form of encrypted electronic signature attached to each email to ensure the content is not modified by hackers along the way.
Finally, there's DMARC, the ultimate set of rules that tell receiving mail servers what to do (reject or send to spam) if an email fails the SPF or DKIM test. If you are administering an open source system and need to send notifications, Configuring SMTP to send email from a WordPress website also requires you to complete the same DNS validation steps. To better understand the technique of setting up these records, please take the time to read the detailed SPF DKIM DMARC anti-spam email instructions.
Track and debug: Leverage Webhooks and email logs to know where emails are
Connecting the email platform's Webhooks to the internal server helps you automatically update email status into the database, supporting the team in quickly handling errors and complaints.
Never keep the mindset of coding and then sending an email and then "putting your baby in the market". Proactively set up Webhooks so that every time an email is "bounced" (returned due to the wrong address), your cloud system will automatically mark that user as inactive (inactive) in the database. This contributes to accurate email performance analysis, saves money on sending error emails, and protects long-term domain reputation. When a customer calls the switchboard complaining "I haven't received the confirmation code", the email Logs data table is the steel evidence for you to look up whether the email was successfully transferred to Gmail/Yahoo or blocked due to a filter error.
In short, in the transactional email race SendGrid vs Mailgun in 2026, we must admit that no platform is absolutely perfect. If you need an easy-to-breathe ecosystem that smoothly integrates both marketing and transaction features with flexible costs at the early stages, SendGrid will be an extremely reasonable companion. On the contrary, if your project is highly technical, needs to handle complex inbound emails and you are a developer who loves absolute control via API, Mailgun is still a monument that is difficult to overthrow. Based on the latest updates, carefully evaluate your budget, team skills, and long-term expansion goals to make the most informed decision.
Are you using SendGrid, Mailgun or another service? What is your actual experience with API speed and inbox rate these days? Please share your opinions and reasons in the comments section below!
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