10 Best Paid and Free Email SMTP Service Relay Providers – Reviewed

Choose from these best SMTP service providers and find a secure solution to your mail deliverability problems.

Understanding SMTP In Brief

Simple Mail Transfer Protocol (SMTP) is the industry standard for sending emails over the internet. Since it uses proper authentication methods for sending a mail, it ensures that the marketing and transactional emails get successfully delivered to the customer’s inbox. Organizations that host their websites on WordPress must be aware of the importance of emails. WordPress uses emails to:

  • Register new accounts
  • Recover lost passwords
  • Send notifications about any changes done

Since there seems to be a delay problem with WordPress’s default method (PHP mail) for sending emails, enterprises need to ensure that their customers get their emails on time! An SMTP service provider comes to their rescue, which helps alleviate their mail delivery problems. Let’s dive into the best SMTP services, which organizations hosting their websites on WordPress can use.

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SMTP.com is a leading SMTP service provider in marketing used by hundreds of thousands of businesses worldwide. SMTP.com offers a robust API to send transactional emails and has an easy to integrate WordPress plugin.
Because SMTP relay is the core focus of their business, they offer some of the best deliverability on the market for extremely high volumes of emails.


SMTP.com offers affordable delivery services and caters to all kinds of businesses. Their plans range from $25 to $500 and above. The best part about this platform is that all the features are available in all the plans. The prices change only based on the volume of emails sent monthly. Even with the lowest price pack, users can get access to 24×7 customer support and all the SMTP tools. The Reputation Defender for list cleaning is an add-on feature available for all users.

SMTP.com’s Email API is available if you wish to integrate your company with an email relay provider.
You can interface with your business using this simple-to-use API infrastructure in under five minutes.
You may find comprehensive API documentation on the SMTP.com website. The integration of the API with your apps is described in this.

Additionally, it describes how to utilize the service, including setting up email accounts and sending emails.
You must try it out!



It has been a reliable SMTP email provider for some time now, which offers a powerful marketing platform with SMS marketing, email marketing, transactional emails, and live chat. It integrates easily with WordPress and other platforms like Salesforce, OptinMonster, Google Analytics, and others. Its API and SMTP service is highly extensible, which improves email delivery.


SendinBlue offers a lifetime free plan with an email restriction of 300 per day. However, users can choose the paid plans from $25 a month, which offer 4,000 emails a month with no sending limit (daily).


  1. Login to the WordPress dashboard
  2. Take the mouse pointer over Plugins and then click on Add New.
  3. Type Sendinblue in the search box
  4. Click on Install Now and then choose Activate.

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  1. After you activate the plugin, an icon will appear on the left side menu. Now, click on  Create an Account.
  2. The software will redirect you to the SendinBlue signup page. You can either use your Gmail account for signing up or create an account manually.
  3. Proceed to enter your profile details. You can even skip this step and fill in the details later.
  4. Choose the plan you would like to choose on the next page.
  5. Then, you will get redirected to the following welcome screen.

hosted smtp



  1. You need to complete your profile and verify the contact number for validating your account.
  2. Open the WordPress dashboard and choose the SendinBlue icon on the left side menu.
  3. Click on get API keys. The following page will open.

email hosting smtp

  1. Copy any of the APIs which are visible here and paste the chosen API in the plugin.
  2. Click on activate. Congratulations! You have activated both your SendinBlue account and plugin.




Developers and businesses who want a popular SMTP Service provider that offers a powerful API for sending transactional emails can choose Mailgun. They can integrate it with their WordPress website quickly and easily. MailGun ensures the users get an SMTP service that is easy to scale according to the business requirements. So whether you are a small business, an eCommerce website, or a membership store, MailGun will offer a scalable platform for your transactional and marketing emails.


Mailgun offers the first 10,000 mails free to its users as part of its ‘pay as you go’ plan, which is sufficient for smaller websites. Users who want improved deliverability with a dedicated IP address can choose the paid plan starting at $79 a month.

Install and Configure

  1. The first step is choosing a domain or subdomain to send emails through your website.

reliable smtp server

  1. Then open your DNS provider’s dashboard and add the listed records on the Mailgun’s configuration page.
  2. Make sure you verify the records to ensure successful configuration on the Mailgun Domains page.

service smtp

  1. Open the WordPress Dashboard and navigate to Plugins.
  2. Now click on add new and search Mailgun for WordPress.

smtp solutions

  1. After installing, you can activate the Mailgun plugin. Then, configure it from the Settings > Mailgun section.



Amazon SES

Amazon Web Services has become the global leader when it comes to cloud computing infrastructure. Amazon also offers a robust cloud-based SMTP service provider (Amazon Simple Email Service), suitable for developers and marketers. They can easily carry out transactional, notification, and marketing email campaigns. It offers high email deliverability and is a cost-efficient choice.


Websites hosted on AWS can use their service free of cost for sending 62,000 emails a month. Other websites have to choose the paid plan, which starts at $0.10 for 1,000 emails.

Signing up and sending emails

AWS Console

  1. Login to your AWS account or create one.
  2. Under Application services, click on SES. Next, navigate to Identity Management.
  3. Click on Domains, then Verify a New Domain.
  4. Next, navigate to email addresses and verify your email address.
  5. Click on SMTP settings and note down the server name and port numbers.
  6. In SMTP settings, choose to Create my SMTP Credentials. After creating, note down the username and password.

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  1.   After logging in to the WordPress dashboard, activate the WP SES plugin (or a similar one).
  2.   Click on Settings > Ex SMTP Mail Setting.
  3.   In the from the field, enter your name.
  4.   Select Send all WordPress emails via SMTP in the Mailer section.
  5.   Make the following changes, and you are good to go!
    1. SMTP Host: Server Name provided by Amazon SES.
    2. SMTP Port: Enter 587, 25 or 465.
    3. Encryption: TLS encryption.
    4. Authentication: Yes: Use SMTP authentication.
    5. Username: Enter the username provided by SES.
    6. Password: Enter the password provided by SES.
    7. Click on Save Changes.

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It is easy to use SMTP service tailored for marketers, businesses, and websites. The key USP is fast email delivery, which comes at simple price options and easy integration. Since designers of Postmark are experts in sending transactional emails, they emphasize deliverability and speed.


Their email service starts from $10 a month, which allows businesses to send 10,000 emails. After that, it is $1.25 for every 1,000 emails.

Setting up

  1.   Download the Postmark plugin for WordPress.
  2.   Upload your postmark directory to the /wp-content/plugins directory.
  3.   In your WordPress admin dashboard, activate the Postmark plugin.
  4.   Click on Settings > Postmark, and enter the Postmark details.
  5.   Send a test email to ensure that the plugin is set up correctly.

outbound smtp server

  1.   After verifying, click on Enable. It will override the wp_mail, and you can start using Postmark to send emails.




It is another cloudbased SMTP service provider which boasts of lightning-fast deliveries. They have servers located across the globe, which help push emails from suitable locations to offer a fast service to its clients and reduce network latency. Other key features of Pepipost include Real-Time Reports, Subaccount Management, Email API to connect your apps, etc.


Users get 30,000 free emails after signing up for 30 days and after that, 100 free emails a day. The starting plan costs $17.5 a month for an annual subscription, allowing users to send 150,000 emails.

Integration with WordPress

It is easy to integrate Pepipost with WordPress. Just follow the following instructions:

  1. Login to your WordPress account and install the Pepipost WordPress Plugin.
  2. After installing, check the left-hand side menu, and it will display the Pepipost plugin. Click on “Pepipost Settings.”
  3. Next, enter the details like API keys, from email, from the name, etc., and you are good to go!

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Elastic Email

Organizations looking for an affordable SMTP service can choose Elastic email. Its key USP is that it offers 150,000 emails a month free of cost. Secondly, it provides an innovative set of suitable tools for designers, marketers, and developers. The global infrastructure helps ensure lightning-fast speeds for transactional emails.


Organizations with small sending needs can feel satisfied with the 150,000 free emails a month. However, if you send a higher number of emails, you can choose from the paid plans ranging from $150 to $4,000.

Getting started

  1.   Sign in to the Elastic Email account.
  2.   Copy the API keys
  3.   Login to the WordPress dashboard and search for the Elastic Email Sender plugin.
  4.   Install the plugin and paste the API keys which you copied earlier from the Elastic Email account.
  5.   Send a test email.

outbound smtp relay




It is another powerful SMTP plugin for WordPress that will allow you to use any SMTP email provider to send emails. The email service is available for free and is easy to set up. Its key USP is to use it to integrate other plugins to WordPress like Mailgun, SendGrid, Gmail, etc.


It is a free plugin, but users can choose the pro version, which starts at $49/year. The Pro version of WP Mail SMTP only supports Microsoft SMTP and Amazon SES.


  1. Login to your WordPress console and install the WP mail SMTP plugin.
  2. Activate the plugin.
  3. Next, visit Settings > WP Mail SMTP to configure the settings.
  4. Here, enter the SMTP settings for using WP mail SMTP.

outbound mail relay



G Suite

Businesses can hang on to the Google interface’s familiarity and still get a professional email address. The advantage of using G Suite is that you get access to the complete productivity suite, including Google Drive, calendar, docs, etc.


The pricing ranges from country to country.

Use WP Mail to setup Gmail mailer in WordPress

  1. Install the WP Mail plugin for WordPress and activate it.
  2. Open WP Mail SMTP > Settings and fill in the following details:
  3. From Email: You can leave the From Email as it is as Google will force it to match your authorized email account.
  4. From Name: is the name linked to the mails which your website will send out.
  5. Return-Path: You can leave the Return Path setting as is.
  6. Mailer: select the Gmail option.
  7. After choosing the mailer, you will see a new section titled Gmail. Create a web application from your Google account and fill in the required details. Your G Suite SMTP is set up!




It is another SMTP service provider which is suitable for small organizations because it is affordable and offers a 98% email deliverability rate. Moosend includes a drag and drop builder interface, which makes designing transactional emails a breeze. It also provides real-time email tracking ability.


It offers a free plan which can include 1,000 subscribers. The paid plans start at $10 for a month.




DuoCircle caters to every email need your business requires, be it protecting the business domain from spoofing and phishing attempts or making sure that your clients are not missing out on the crucial emails sent from your domain by maintaining a high sender reputation. Hence, it’s an excellent choice for businesses looking for an all-in-one solution for their email needs.


Available for free up to 1,000 monthly messages. Further, paid plans are also very affordable if your business has a higher requirement or you want to run a marketing campaign targeting thousands of potential customers, starting at $4/month for 2,500 messages, $11 for 12,500 messages, and so on.


Now that we’ve seen some of the best SMTP services available to deliver your business emails, here’s a summary of all the ten given services for you to make an informed choice for your business.

    Key Features   Cost
  • Competitive pricing
  • Variety of automation features
  • Customizable email templates
  • The free plan offers 300 emails a day
  • Paid plans start at $25 a month
  • Incredibly powerful
  • Supports testing mode
  • Suitable for developers
  • 10,000 emails free for a month
  • The paid plan starts at $79 a month
Amazon SES
  • Competitive prices
  • Offers high email deliverability.
  • Free of cost for websites hosted on Amazon for 62,000 emails a month
  • The paid plan starts at $0.10 for 1,000 emails
  • Detailed analytics
  • Multiple server locations
  • Plans start at $10 for a month (10,000 mails)
  • Real-Time Reports
  • Sub Account Management
  • Email API to connect various apps
  • Thirty thousand free emails after signing up for 30 days
  • $17.5 a month for 150,000 emails
Elastic Email
  • Innovative tools for designers, marketers, and developer
  • Offers A/X testing
  • 150,000 free emails a month
  • Paid plans range from $150 to $4000
  • Works with all the email services.
  • Offers native Amazon SES and Microsoft integrations
  • Offers full control over email notifications
  • Pricing starts at $49 for a year
G Suite
  • Super cheap
  • Suitable for small organizations
  • Reliable infrastructure
  • Varies from country to country
  • Affordable plans
  • Easy to use A/B testing options
  • Good customer support
  • Free for up to 1,000 subscribers
  • The paid plan starts at $10 for a month
  • Flexible & Affordable pricing
  • DKIM signing with every plan
  • Real-time reports & analytics
  • Protection against virus attacks in case your network is compromised
  • TLS Encryption for more secure email delivery
  • Multiple ports available for relay mail
  • 24/7 email, chat, and phone support
  • 30-day money-back guarantee
  • 1,000 free emails for every user
  • Paid plans start at $4/month for 2,500 emails and go up to $550/month for one-million emails



Final Words

The SMTP services, as mentioned above, offer powerful features at affordable rates. The key to choosing the best service is to look at the service’s email deliverability rates, high scalability, budget, and the most crucial part, on-the-go customer support so that you do not lose any business time in case there is a mishap. Thus, organizations can choose the most suitable option considering the above points to ensure their clients and potential customers get their emails always delivered on time!

Join the thousands of organizations that use DuoCircle

Find out how affordable it is for your organization today and be pleasantly surprised.

Interested in our Partner Program for MSPs and VARs? Visit Our MSP Partner Program.

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