Mailgun vs. SendGrid: which is the best email service provider?

mailgun logo sendgrid logo

There are two main types of email to consider in your business: bulk email and transactional email.

With bulk email – or email marketing – you create a standard email campaign and send it to multiple subscribers at once.

But with transactional email, the recipient triggers the email themselves – such as by opening an account, making an order or asking for a password reminder.

Because your recipient is expecting a response, it's crucial to have an email tool with high deliverability. You can't let your email end up in spam, or be delivered three hours later. You also need a tool that balances user-friendliness with enough complexity to customize it according to your needs.

When it comes to choosing a transactional email tool, there's no such thing as one size fits all. But with the range of excellent tools on the market, there's more choice and scope for flexibility than ever before.

Two of the best transactional email tools are Mailgun and SendGrid, which we'll weigh up here based on features, pricing, ease of use and ideal use cases.

SendGrid vs. Mailgun comparison – what's the difference between the tools?

Mailgun markets itself as "The Email Service for Developers", offering powerful APIs that enable you to send, receive and track email effortlessly. Mailgun boasts a 99.99% uptime SLA and provides their services to 150,000+ businesses, including those benefiting from their generous 10,000 free emails a month.

SendGrid's offering is more diverse. In addition to being one of the best transactional email tools on the market, it also offers email marketing features including design templates. SendGrid is a leader in trusted email delivery for over 80,000 paying customers who use their service to send over 50 billion emails every month.

Both Mailgun and SendGrid have an all-star client list on their homepage, such as GitHub and Shopify for Mailgun, and Uber and Airbnb for SendGrid. They also include additional features like analytics, segmentation via tags, and an email templates API.With their powerful feature sets, it's no surprise they're trusted by the crème de la crème.

When to choose Mailgun

1. You want ease of use

Mailgun offers brilliant API documentation, including libraries for popular languages like Python, Ruby, Java, C# and PHP, so developers can easily integrate email into their app.

Mailgun has a tribe of supporters on G2 Crowd, many of whom applaud the software's top-class ease of use and implementation. As of September 2019, Mailgun is rated 9.0 for ease of use, 9.0 for ease of admin, and 9.1 for ease of admin. For comparison, SendGrid averages 8.3 in these metrics. To make their email tool even more user-friendly, Mailgun also launched a new UI as of April 2019.


2. You want to send email marketing with flexible APIs

As they make clear on their website, Mailgun is an email service for developers – not marketers. While it is a fact that SendGrid offers a very broad email marketing functionality, you can also send emails from Mailgun either through SMTP relays or through our RESTful HTTP API, making it easy for senders to scale how they see fit. However, it certainly hasn't invested in it to the same extent as SendGrid who has made really easy for marketers to create and send emails.

3. You want to cut down on spam and throwaway emails

Mailgun’s email validation service is also popular among its users. It runs in real time and bulk tests on your emails to check that they actually exist. This cuts down on bounces and boosts your overall deliverability.

MailGun email validation

Another perk: they have built a real-time suggestion service into their email validation service. When the tool picks up on a common typo (e.g. "" instead of ""), it'll return it along with invalid status, so you can offer the suggestion to your user.

4. You're not sending millions of emails just yet

Mailgun tends to be the best choice for small sites and businesses that need a transactional email solution, but probably won't be sending millions of emails from the get-go.

Mailgun offers a generous 10,000 monthly emails for free, so if you see yourself sending less than that number some months, their email service could be a cost-effective solution.

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When to choose SendGrid

1. You want more complexity

SendGrid isn't the most simple email service on the market, but for many developers, that's a good thing. Their software is extremely customizable.

As a SendGrid customer, you can benefit from their RESTful APIs that are built on HTTP and return JSON for clear implementation. And with their comprehensive open-source libraries, you can code in your preferred language and consult use cases in Node.JS, Ruby, Python, Go, PHP, Java and C#.


SendGrid’s Pro plan (starting at $79.95/month) includes a dedicated IP address, as well as dedicated IP warm up to gradually increase your email traffic automatically and pooling to send emails to control groups across multiple dedicated IP addresses.

Mailgun also includes one dedicated IP address with plans starting from $79/month.

2. You want to send marketing emails with the same tool

If you want great API/SMTP and email marketing features, SendGrid is your best choice. Although Mailgun lists email marketing functionality, it's less developed than SendGrid's for now.

SendGrid has all the usual features for transactional emails, but offers the added benefit of email marketing services, which you can add to your subscription. This means that you can manage your transactional email and email marketing campaigns from the same dashboard.

With SendGrid Marketing Campaigns, it's free to store up to 2,000 contacts and send up to 6,000 emails/month. Alternatively, the Basic plan starts at $15/month to send up to 5,000 contacts and 15,000 emails/month.


However, SendGrid's complexity also applies here. If you need a user-friendly tool for your whole team, including less tech-savvy teammates, you might be better off integrating SendGrid with a more accessible email marketing tool.

3. You're working at scale

Although neither tool will let you down when you need to unexpectedly send a million emails on a Monday morning, larger enterprises tend to choose SendGrid over Mailgun. It generally allows for greater flexibility and gives you more for your money when sending high volumes.

4. You want top deliverability

Does Mailgun or SendGrid have better deliverability? It's hard to say, but SendGrid seems to nudge ahead here. SendGrid has led the way for transactional email since the company started in 2009 – and it's only gotten stronger since. SendGrid prides itself on its deliverability, scalability and in-depth email expertise.

SendGrid 07-Deliverability

SendGrid shares that customers who use their Expert Services have a 97% average delivery rate, compared to the 85% industry average.

It's harder to find data on Mailgun deliverability, although they also offer a managed deliverability service to provide API support, IP and domain reputation management, ongoing consulting and proactive monitoring of your email program.

Pricing – is SendGrid or Mailgun a better deal?

How much you pay for Mailgun or SendGrid depends on how many emails you need to send and what you need to do with the tool.

Both Mailgun and SendGrid offer certain features for free. Mailgun has a free forever plan (their Concept plan), while SendGrid gives you 40,000 free emails for your first 30 days then 100/day forever.

What you get for free with Mailgun and SendGrid pricing plans:

10,000 emails / month40,000 emails for 30 days, then 100/day forever
100 validations / monthTransactional template editor
5 days of log retentionEmail analytics
24/7 ticket supportTicket support

Here's how SendGrid pricing vs. Mailgun pricing compare when it comes to sending 20,000, 200,000, and two million emails per month:

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The recap – comparing Mailgun vs. SendGrid and how to choose the best email service for your business

Both Mailgun and SendGrid eliminate the pain points of managing your own server and radically simplify transactional email for developers. When comparing the two tools, the difference between them is subtle.

A summary of how to know when SendGrid or Mailgun is best for your business:

When Mailgun is bestWhen SendGrid is best
You want ease of useYou want more complexity
You don't need to send marketing emailsYou want to send marketing emails with the same tool
You want to cut down on spam and throwaway emailsYou want top deliverability
You're not sending millions of emails just yetYou're working at scale

Whether you decide that Mailgun or SendGrid is better for your business, you're going to be using one of the best email services on the market.

To make it the best possible addition to your tech stack, make sure to connect it to your other tools using an iPaaS solution like PieSync.

See the connections you can make between hundreds of tools with more added every week, then get started with a free trial.

About Lucy Fuggle

Lucy Fuggle writes for PieSync, the two-way contact sync tool for hundreds of apps. She also works with her clients to make their brand matter with a content-rich marketing strategy.