9 Best SMTP Services for Reliable Transactional Emails

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Best SMTP Service Providers for Fast & Reliable Transactional Emails

Are you looking for the best SMTP provider to ensure your emails are delivered?

Transactional emails are a pivotal part of running any online business. Customers and subscribers expect to receive email notifications about their orders and any changes to their account.

In order to ensure these emails go through successfully, you need an SMTP service.

If you run a WordPress site, you’ve likely struggled to make sure your transactional emails get through to inboxes.

WordPress relies on PHP to send emails. However, it often isn’t configured properly or is disabled by hosts to avoid abuse.

SMTP services offer an easy and secure solution to this problem.

In this post, we’re sharing some of the best SMTP providers so you can pick the right one for your site.

What Is SMTP?

SMTP (Simple Mail Transfer Protocol) is the communication protocol used for sending and receiving emails, and it’s a fundamental component of the email infrastructure. In fact, SMTP is the industry standard for sending emails on the internet.

If you run a website that sends transactional emails, an SMTP provider will authenticate your site’s identity and make sure your emails are delivered. Your notifications will also be less likely to end up in customers’ spam folders.

What sorts of emails do you need an SMTP service for?

Websites rely on transactional email for various things like:

  • Registering a new account
  • Recovering lost passwords
  • Notifications for password changes, new posts, and comments.
  • Order confirmations
  • Invoices
  • Shipping and delivery notifications

If these emails don’t go through, you’ll quickly lose customer trust. Or in the case of password recovery, your site could be rendered unusable for some visitors.

Transactional emails are not only an important part of your email marketing. They’re absolutely vital to running your business.

SMTP Integration With WordPress

First, if you have a WordPress site, you’ll need to install an SMTP plugin. Then, you’ll be able to seamlessly integrate WordPress with any of the SMTP service providers we’re about to cover.

Here is our recommendation for the best SMTP plugin:


Wp Mail SMTP Homepage

WP Mail SMTP is the best WordPress SMTP plugin, and it allows you to easily send WordPress emails using any SMTP email service provider. Plus, it’s super easy to set up.

It’s available as a free SMTP plugin, or you can upgrade to the Pro plugin to get access to more features.

And, if all of this SMTP stuff makes your head hurt, you can sign up for the Elite plan and get White Glove Setup to have an expert from their team set up your SMTP service for you. White Glove Setup is available for SendLayer, SMTP.com, and Brevo, which are our top 3 suggestions for SMTP providers.


  • Free for the basic plugin
  • $49 per year for Pro plan (1 site)
  • $99 per year for Elite plan (1 site with White Glove Setup and Priority support)
  • $199 per year for Developer plan (20 sites)
  • $399 per year for Agency plan (100 sites)

If you decide to go with WP Mail SMTP, you’ll need to do 2 things:

Best SMTP Service Providers For Dependable Transactional Emails

Now, let’s dive into our list of the best SMTP services available. This post includes both paid and free SMTP server providers.

If you have a specific one you’re interested in, feel free to use these links to jump directly to it:

1. SendLayer

SendLayer is a dedicated SMTP email delivery service that integrates with over 1,000 platforms. No matter what type of website or eCommerce store you run, SendLayer will keep your transactional emails going smoothly.

SendLayer lets you authorize your domain name, so email service providers, such as Gmail or Outlook, won’t flag your messages as spam.

Its clean and simple dashboard lets you easily monitor your email analytics and account details.

SendLayer also helps your website’s speed and performance. By taking on the burden of handling your transactional emails, this SMTP provider will keep your web pages loading quickly.

As with most of the tools on this list, pricing depends on the number of emails you’ll send each month.


  • Fast and reliable email delivery
  • Sender reputation protection
  • Easy to set up, use, and monitor
  • Email list management
  • Seamless integrations
  • Excellent customer support


  • The Growth Plan tops out at 10,000 emails per month. If you send a higher email volume than that, you must request a quote.


  • $5 per month for 1,000 monthly emails
  • $15 per month for 5,000 monthly emails
  • $25 per month for 10,000 monthly emails
  • Scale plans available for 20,000+ emails

Get Started With SendLayer

2. SMTP.com

smtp homepage

SMTP.com is one of the most powerful email delivery services on the market. Not only can it handle large volumes, but it also ensures speedy delivery.

It’s built on a highly responsive infrastructure that ensures there are no delays.

SMTP.com lets you set up, integrate, and start sending emails in minutes.

Their Reputation Defender addon proactively monitors your email list health. It protects your domain and IP reputation and ensures high delivery rates.

SMTP.com also gives you comprehensive reports so you can check and improve your email delivery and engagement performance.

It meets the needs of businesses and developers alike and has affordable plans for all.


  • It supports shared IPs and dedicated IPs, for better sender authentication
  • Flexible and scalable plans
  • Proactively checks and blocks spam and maintains high delivery rates
  • Superfast delivery with over 99% system uptime
  • It has a highly responsive support team that’s available 24/7
  • Effortless migration from other services


  • The Reputation Defender addon costs an extra 20% of the plan’s price.
  • There are no plans cheaper plan options for websites sending fewer than 50,000 emails a month. That means it may not be the best choice for small businesses.


  • $25 per month for 50,000 monthly emails, up to $500 per month for 1 million monthly emails
  • High-volume plans available for 250 million monthly emails

Get Started With SMTP.com

3. Brevo (formerly Sendinblue)

Marketing Automation Tools - Brevo

Brevo (formerly Sendinblue) is a popular email marketing service that also offers SMS marketing. In short, it’s an all-in-one marketing platform.

Their transactional email product is also one of the best SMTP service providers on the market.

This SMTP email provider works great with WordPress and other marketing tools like OptinMonster, Google Analytics, and more.

Brevo has an extendable API and SMTP relay service that improves email delivery rates for transactional emails. That means more of your emails will go to your audience’s inbox rather than their spam folders.

Pricing plans are dependent on sending limits rather than the number of contacts. This gives Brevo a unique advantage for small businesses looking to scale.

You have 2 options for using Brevo’s SMTP services:

  • Sign up for their standalone transactional platform. If you already have your email marketing set up through Constant Contact or another service, then this standalone product may be right for you.
  • Sign up for their full marketing platform, which includes transactional emails. Brevo is also one of our favorite email marketing platforms, so you can’t go wrong with this option.

Either way, you can send up to 300 emails a day with Brevo’s free plan, making this a great option for small businesses or new eCommerce sites.


  • Inexpensive and competitive pricing
  • Variety of automation features for email marketing
  • Intuitive, easy-to-use interface
  • Customizable email templates
  • Email tracking for results optimization


  • Support is a bit on the slow side. There is no live chat, just a form to create a support ticket.


  • Free for up to 300 emails per day
  • Transactional Platform plans start at $15 per month for up to 20,000 emails a month
  • Full Marketing Platform plans start at $25 per month

Get Started With Brevo

4. Mailgun

Screenshot of Mailgun's home page

Mailgun is another powerful transactional email platform. It’s a particularly good choice for developers because of its robust API options. With Mailgun, you can send, receive, and track transactional emails.

Plus, Mailgun is an easy-to-scale SMTP service. Sending marketing and transactional emails shouldn’t be a problem regardless of what type of site you’re running: eCommerce store, small consulting business, membership website, or something else entirely.

This SMTP service is great for medium businesses who want their emails to go where they belong: your audience’s inbox.


  • Incredibly powerful
  • Supports testing mode
  • Great for developers: in addition to SMTP relay services, it offers RESTful API and API libraries for programming languages such as Ruby, Python, PHP, Java, C#, and more


  • Lacks beginner-friendly features of other SMTP providers on our list


  • $35 per month for the Foundation plan with up to 50,000 emails per month
  • $90 per month for the Scale plan, which includes 100,00 emails and dedicated IP tools
  • Both the Foundation and Scale plans have flexible pricing for higher numbers of emails
  • For Enterprise customers, Mailgun offers custom pricing

5. SendGrid

Homepage for Sendgrid

SendGrid is a cloud-based email service provider that also offers an SMTP service. With SendGrid, you can send and receive bulk emails without managing an SMTP server. And, you can create email marketing campaigns!

SendGrid offers easy setup, excellent scalability, delivery optimization tools, dedicated IP addresses, plenty of integrations, and more. It also provides complete analytics and real-time feedback on every email you send.

Like Brevo above, SendGrid offers 2 separate products

  • Email API/SMTP plans geared toward developers
  • Marketing Campaign plans geared toward marketers

The good news? Both types of plans include their SMTP and API functionality.


  • SendGrid boasts a 99% deliverability rate among its 134 billion daily emails
  • Seamless integration with WordPress via the plugin
  • Responsive and helpful customer support


  • Paid plans that include a dedicated IP might be too pricey for new businesses


  • There are free options for both types of plans.
  • Email API/SMTP plans start at $19.95 per month for the Essentials 50K plan. However, if you want a dedicated IP, you’ll need the Pro 100K plan, which starts at $89.95 per month.
  • Marketing Campaign plans start at $15 per month for the Basic plan. But you’ll need the Advanced plan for a dedicated IP. It starts at $60 per month.

6. Amazon SES

Homepage for Amazon SES

Amazon Simple Email Service (Amazon SES) is a flexible and scalable SMTP service for developers and marketers to send marketing, notification, and transactional emails.

This SMTP service offers high deliverability and powerful features but is mostly geared towards developers and advanced users.

Amazon SES does one thing (deliver emails), but it does it well. If you have more expertise than money, this may be the best SMTP service for you.


  • One of the most competitive prices on the market
  • If you’re hosting your web application on Amazon EC2, you get 62,000 free emails each month


  • In order to get customer support, you have to purchase a separate Amazon Web Services (AWS) support plan.
  • Requires a good deal of technical knowledge


  • If you send emails using an application hosted in Amazon EC2 (U.S.): Free for the first 62,000 each month ($0.10 for every 1,000 over)
  • $0.10 for every 1000 emails you send from an email client or other software (U.S.)
  • $0.12 for each GB of attachments

7. Postmark


Postmark is one of the best SMTP services that specialize in sending transactional emails, so you just know they’re focused on email deliverability and speed.

This mail client offers excellent analytics and security, as well as mobile-friendly responsive email templates, message events that can be triggered with simple webhooks, and more.


  • Detailed analytics with 45 days’ worth of email logs showing emails sent, received, who received them, who read them, and who marked them as spam. You can also adjust the data retention setting to whatever you need.
  • Due to its singular focus on delivering transactional emails, Postmark has some of the fastest delivery times in the industry


  • It’s fairly expensive for a tool with such a singular focus
  • It won’t help you with email newsletters or other marketing campaigns


  • Free for 100 emails per month
  • $15/month for 10,000 monthly emails
  • $55 /month for 50,000 monthly emails
  • Postmark’s pricing continues to scale up, with users approaching 2 million emails paying over $1000/month

8. Google Workspace (formerly G Suite)

Homepage of Google Workspace, which can be used as an SMTP provider

Did you know that you can use your existing Google Workspace account as your SMTP service?

Google Workspace lets you create a professional business email address while still hanging onto the familiarity of the Google interface. Plus, you get access to the entire productivity suite: Google Calendar, Drive, Docs, and more.

Using the WP Mail SMTP plugin, you can connect your WordPress website to Google’s SMTP server. Then you can send your transactional emails through the world’s most popular email service provider.

Want to learn more? Check out this article:

How to Set Up WP Mail SMTP With Gmail [Step by Step]


  • Super cheap
  • Great for small businesses
  • Reliable infrastructure


  • Limited to 2000 messages/day


  • Plans start at $6/month per user
  • Free if you already use Google Workspace for your business

9. Moosend


Moosend is an affordable email marketing platform with SMTP functionality.

This SMTP transactional email service includes a drag-and-drop email builder that makes it super easy to design transactional emails. You can also create and send an email blast and track the emails in real time.

Moosend doesn’t offer a standalone SMTP service. However, if you’re looking for one product for your marketing emails and transactional emails, you should consider Moosend.


  • Affordable email marketing plans that include SMTP service
  • Simple and easy-to-use A/B testing options
  • Great customer support
  • Robust tools for email list segmentation


  • If you already have an email marketing platform that you’re happy with, then Moosend isn’t the right choice for SMTP
  • No dedicated IP in their standard plans


  • A wide range of pricing, ranging from $7/month for 500 subscribers to $4,672/month for 1 million subscribers
  • Custom pricing for Enterprise plans, which include an account manager, dedicated IP, and priority support.

Choosing the Best SMTP Services

There are so many SMTP service providers out there that let you send mass emails, WordPress emails, transactional emails, and any other kind of email you can think of.

What’s really important when choosing an SMTP service is:

  • Email deliverability
  • Scalability
  • Budget

Based on these criteria, SendLayer is our top pick for a dedicated SMTP provider. It offers robust tools for transactional emails at a scalable price.

If you don’t yet have an email marketing platform, then Brevo (formerly Sendinblue) is a smart and affordable option for all your marketing emails, including transactional emails.

However, no one tool is best for everyone. Any SMTP mail server on this list could be the best choice for your business.

Plus, there are even more options out there. For instance, if you already use Mailchimp, you may want to use their transactional email service called Mandrill. Or, if your business already has Microsoft Office 365, you can use it for your SMTP service.

There you have it! We hope you found this article about SMTP services for reliable email marketing super informative. To push your email strategy to a higher level, check out these guides:

These articles are packed with info to help you better your email marketing strategy to optimize results and grow your business.

And if you’re looking to build your email subscriber list and generate leads, you may want to check out OptinMonster.

It’s the most powerful lead generation tool to grow your subscriber list. It makes it easy to create stunning popups, floating bars, scroll boxes, and other email campaigns that convert visitors into subscribers.

Want to start building your list right away? Get OptinMonster today.

Disclosure: Our content is reader-supported. This means if you click on some of our links, then we may earn a commission. We only recommend products that we believe will add value to our readers.

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