9 Best SMTP Service Providers for Reliable Email Delivery

best smtp service providers

Looking for the best SMTP service providers to deliver your emails without fail?

Emails are essential to communicate with your audience, keep them engaged in your brand, and drive traffic back to your site. But many business owners face deliverability issues where their emails end up in the customer’s spam or junk folder.

With the help of an SMTP service, you can rest assured that the emails you send from your website will reach your user’s inbox successfully.

In this article, we’ve picked the best and most reliable SMTP relay service providers to improve your email deliverability.

Before we start, let’s cover what SMTP is and why you need an SMTP service provider for your WordPress site.

What is SMTP?

SMTP (Simple Mail Transfer Protocol) is a set of guidelines that are used to transfer electronic messages or emails on the internet.

When you send an email, SMTP processes it and figures out which mail service the recipient is using. Then, it sends all the information to the service which downloads the email content and adds it to the recipient’s inbox.

It uses proper authentication which increases the chances of your emails being delivered to the users’ inbox without landing in the spam folder.

Why Do You Need an SMTP Service Provider?

If you own a WordPress site, you must know that emails are used for various reasons. Some of them are:

  • Registering new users
  • Recovering lost password
  • Notifying users about comments, new posts, and password changes
  • Sending customer order confirmation, invoices, and delivery details

However, there is a problem with WordPress emails. It uses the PHP mail() function to send emails to users from your website.

And many hosting providers don’t have this function properly configured. Some even disable it to prevent server abuse and attacks. So your emails are more likely to be undelivered.

Even if the function is configured, sometimes emails are still categorized as spam. That’s because most spam filters verify your email by sender email, location, domain name, and flag it as suspicious.

The best way to eliminate this problem is using a reliable SMTP service provider. This ensures that your emails are successfully delivered to the recipients’ inboxes.

At the same time, you won’t have to worry about the limit on how many emails you can send. You’ll even be able to send bulk emails in just one click.

That said, let’s look at our list of the best SMTP service providers so you can send emails from your website without any hiccups.

Best SMTP Service Providers

There are many SMTP service providers available on the market. Each of them offers unique features and has different pricing.

To find the best SMTP service provider, you need to consider many factors such as ease of use, high delivery rates, the number of emails that you can send, and more.

We’ve reviewed the best SMTP service providers that offer the best features to send transactional emails and run your email campaigns. So let’s dive in!

1. WP Mail SMTP

wp mail smtp

To connect to an SMTP service to your WordPress site, you need an SMTP plugin. And WP Mail SMTP is the best SMTP plugin that lets you easily send WordPress emails using any SMTP email provider.

With WP Mail SMTP, you can easily fix the WordPress email issue by setting up the email options and the SMTP service of your choice. It integrates seamlessly with all the major providers such as SMTP.com, Sendinblue, Amazon SES, Mailgun, and more.

The great thing about WP Mail SMTP is that it is available for free at WordPress.org.

The plugin is easy to set up and it comes with an onscreen guide so you can configure the right settings without any help, even if you’re a beginner. Then you can test the connection and start sending your emails in no time.

For more advanced features like email log and tracking, you can upgrade to their premium plans. They also offer a white glove setup option with their Elite plan to get your SMTP service set up by a team of experts.


  • Integration with all popular SMTP service providers
  • Automatic tracking of all WordPress emails sent
  • Notification control option
  • Email reporting system
  • Fully translation ready
  • Email open and click tracking
  • Outstanding customer support


WP Mail SMTP is free so you can download the plugin from the WordPress repository. It also offers premium plans starting at $49 per year.

Get started with WP Mail SMTP!



SMTP is the most powerful email delivery service that you can find. It is also a popular service as it is trusted by over 100,000 companies like Best Buy and T-Mobile.

This SMTP service provider ensures that you can send and track a large volume of emails with fast and successful delivery.

It is super easy to set up and also integrates with WordPress plugins like WP Mail SMTP. So, you can connect it with your WordPress site and send emails without any delay.

SMTP lets you send any type of email such as email notifications, registration emails, order confirmations, and other transactional emails to your users.

Another reason to love SMTP is that it offers an SMTP Reputation Defender addon. This addon helps you monitor your email list health, protect your domain and IP reputation. It also makes sure your emails are delivered correctly.


  • Easy migration option from other services
  • 99% system uptime
  • Proactively checks and blocks spam
  • Supports shared and dedicated IPs
  • Flexible and scalable plans
  • 24/7 customer support


SMTP offers a 30-day free trial that lets you send up to 50,000 emails. The paid plans start at $25 per month.

Get started with SMTP!

3. Sendinblue


Sendinblue is another SMTP service provider that is perfect for beginners and small businesses. It also offers the best email marketing services to grow your audience.

So you can send user-triggered transactional emails and targeted marketing emails to your subscribers with Sendinblue. This service works well with WordPress and other marketing tools such as OptinMonster, Google Analytics, and more.

Other than this, Sendinblue also offers powerful features like live chat, SMS marketing, automation, segmentation, and much more.

Sendinblue has a highly extensive API and SMTP relay service which improves your email delivery rates for your transactional emails.


  • Automation features for email marketing
  • Intuitive user interface
  • Customizable email templates
  • Detailed analytics dashboard
  • Integration with WordPress, Magento, Shopify, and more
  • Shared inbox for managing customer email history


Sendinblue offers a free plan that lets you send up to 300 emails per day to unlimited contacts. For unlimited emails and more features, you can upgrade to a paid plan starting at $25 per month.

Get started with Sendinblue!

4. Constant Contact

constant contact

Constant Contact is a popular email marketing and SMTP service. It comes with an easy drag and drop editor so you can create attention-grabbing emails without any trouble.

When it comes to fast and reliable email delivery, Constant Contact is one of the best email services. It boasts a high delivery rate of 97% so you can be sure that your emails will be sent to the users’ inboxes.

Also, Constant Contact’s email authentication allows you to build a good reputation with ISPs (internet service providers) and improve your email deliverability.

Additionally, it offers email marketing tools such as marketing automation and list segmentation so you can grow and maintain your email list.


  • Email automation based on user behavior
  • Real-time reporting and analytics
  • A/B testing for different email subject line
  • Email template and template builder
  • Integrations with WordPress, WooCommerce, and more


Constant Contact pricing starts at $20 per month. They also offer a 60-day trial that you use for free.

Get started with Constant Contact!

5. Mailgun

mailgun best smtp service

Next on our list of the best SMTP service providers is MailGun. It is an SMTP service that uses APIs to send transactional emails and bulk emails. It guarantees higher delivery rates and is a perfect solution for developers and businesses.

Mailgun also integrates with the popular WP Mail SMTP plugin. So, you can easily connect this service to your WordPress emails.

With Mailgun, you get access to features such as accurate email verification, advanced email analytics, and more.

This SMTP service is designed mostly for developers so beginners may have a hard time navigating and using it.


  • Highly scalable SMTP service
  • Email APIs, SMTP relay, and webhooks
  • Supports testing mode
  • 99.99% guaranteed uptime
  • API reference with code samples for Python, PHP, Java, and others


Mailgun’s Flex plan lets you send 5,000 free emails per month for 3 months. After that, you only need to pay for what you send. For a dedicated IP, pricing starts at $35 per month.

Get started with Mailgun!

6. SendGrid

sendgrid best smtp service

SendGrid is a cloud-based SMTP email service provider that lets you send and receive mass emails without having to manage an SMTP server.

With SendGrid, you get access to powerful delivery optimization tools such as dedicated IP addresses, domain authentication, and more. So you can improve your email delivery rates even more.

It also offers useful features such as email analytics, email templates, email editor, and third-party integrations.


  • Integration with WP Mail SMTP
  • Highly responsive customer support
  • Beginner-friendly interface
  • Delivery optimization tools
  • Detailed analytics


SendGrid offers a free plan that lets you send 100 emails per day. Paid plans with higher email quotas start at $14.95 per month.

Get started with SendGrid!

7. Amazon SES

amazon ses best wordpress smtp services

Amazon SES or Amazon Simple Email Service is a highly scalable cloud-based email service. It is a product of the leading cloud computing service company, Amazon Web Services.

You can use this email service to send transactional emails, marketing emails, and bulk emails reliably. It guarantees high deliverability and advanced features for technical users and developers.

Amazon SES also offers features such as content filtering, dedicated IP addresses, and a dashboard to monitor and improve your sender reputation.

If you want to use this service for your WordPress site, then you can integrate it with the WP Mail SMTP plugin.


  • Content filtering and dedicated IP addresses
  • Sender reputation dashboard
  • Detailed statistics and insights
  • Easy integration with WordPress via plugins


Websites hosted with AWS can send up to 62,000 emails per month for free. For other websites, pricing starts at $ 0.10 for every 1,000 emails sent.

Get started with Amazon SES!

8. Google Workspace

google workspace best smtp services

Google Workspace, formerly known as G Suite, is a collection of productivity and collaboration tools such as email, calendar, online storage, Google Docs, and more.

With Google Workspace, you can rely on Google SMTP servers to send out your emails. It lets you set up your own business email address with the familiar Google interface.

You can even set up an account for your WordPress site and connect it to send WordPress emails. Using the WP Mail SMTP plugin, you can set it up in a few clicks.

This service is best for small to medium-sized businesses as you can only send up to 2,000 messages per day.


  • User-friendly interface
  • Custom business email
  • Reliable email delivery
  • Phishing and spam protection


Pricing plans start at $6 per month for one user.

Get started with Google Workspace!

9. Postmark

postmark best smtp service

Last but not the least, Postmark is a popular SMTP provider that is used by companies like Asana, LiveChat, Moz, and others. It offers fast email delivery with simple pricing plans.

They specialize in sending transactional emails with reliable delivery and speed. Along with that, you also get features such as email analytics, account security, email template, and more.


  • Detailed email logs
  • Email templates
  • Multiple server locations (in US, Amsterdam, and Singapore)
  • Open, click and link tracking
  • Helpful documentation and customer support


Pricing starts at $10 per month for the first 1,000 emails. Then, you need to pay an additional $1.25 per 1,000 emails.

Get started with Postmark!

Which is the Best SMTP Service Provider?

The best SMTP service for you depends on the needs and requirements of your business. If you own a WordPress site, you definitely need the WP Mail SMTP plugin to seamlessly connect with any SMTP service provider you want.

For small businesses, we recommend using SMTP.com. It offers fast email delivery rates and flexible features at affordable pricing. You also get reliable customer support.

For larger businesses, our pick is Amazon SES as it is the most cost-efficient SMTP service provider for large numbers of emails.

And that’s it! We hope this post helped you find the best SMTP service provider for your business.

Next, you can check these resources out:

The first 2 posts will help you grow your email marketing list and enhance your SEO. The last one will help you add a contact form on any part of your site so you can generate more leads.

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