A Complete Guide to WP Mail SMTP Mailers

Are you trying to decide the best way to improve email deliverability on your WordPress site? WP Mail SMTP provides you with several options (called “mailers”), which let you choose the specific tool that will help your emails deliver successfully.

In this guide, we’ll share a quick overview of each mailer in WP Mail SMTP so that you can more easily decide which is the best fit for your site.


How Do These Mailers Fix Email Delivery Issues?

While each mailer in WP Mail SMTP works differently, they all serve an important function: authentication.

When an inbox provider (like Google, Outlook, etc) receives a new email, it will check to see if that email seems legitimate. One of the most important things they’ll check is whether the email has been authenticated. In other words, was the email actually sent from the site that it claims to be sent from.

Most of us never see this information in the emails we receive, but our inbox providers are checking over these details very carefully. And as the spamming industry continues to grow (and get more clever), inbox providers are getting even more strict about which emails they’ll allow to be delivered. If the email doesn’t pass these checks, then it may end up in the recipient’s spam box — or it may never get delivered at all.

When you set up a mailer in WP Mail SMTP, it will add this authentication to each of your emails. The exact method for this will depend on the mailer you choose, but the target result is all the same: authenticating your emails so that they arrive in inboxes successfully.

Setting up a mailer will also help in cases where emails can’t send properly because of server configuration issues (some servers aren’t set up to use the WordPress mailing function). Since these mailers will replace the default WordPress mailing function, they allow your site to get around any issues like this.

Each mailer has a different approach to solving your site’s email delivery issues, and also different requirements. In the sections below, you can check out a quick overview of each mailer option in WP Mail SMTP to determine which option is the best fit for your WordPress site.

SMTP.com

SMTP com

Recommended: SMTP.com is a recommended mailer.

SMTP.com has been improving email delivery for over 20 years, and have a strong reputation for reliability. They offer a free trial, after which a paid account is required (but at competitive pricing). And importantly, their setup process is fairly simple compared to many comparable services.

  • Cost: Free for up to 50,000 emails in the first 30 days. After this trial period, a paid account is required (you can check out SMTP.com’s pricing page for all plan options).
  • From Email Requirements: For reliable email delivery, you’ll need a domain-specific From Email (ie pattie@example.com).
  • Bottom Line: SMTP.com is a recommended mailer because they are industry leaders for email delivery. And while many similar services require a pretty extensive setup process, SMTP.com has kept their requirements as simple as possible.

Get Started with SMTP.com

Check out our step-by-step setup guide for the SMTP.com mailer.

Mailgun

mailgun

Mailgun is a popular and super reliable tool for improving email delivery. It also uses a secure API and has a 3 month free trial. After that trial, a paid account is required — however, their pricing is super competitive (as low as $0.80 USD/ 1,000 emails). It’s also worth noting that you’ll need a credit card to create a Mailgun account.

  • Cost: Free for up to 5,000 emails per month during your first 3 months. After that, pricing options start at $0.80 USD per 1,000 emails sent.
  • From Email Requirements: Works with any From Email, but we highly recommend using a domain-specific email for best reliability.
  • Bottom Line: Mailgun is one of the most reliable email delivery options around, and has super competitive pricing. However, it does require DNS access to set up.

Check out our step-by-step setup guide for the Mailgun mailer.

SendGrid

sendgrid

SendGrid is a solid service commonly used to reliably send emails. Much like Mailgun, it uses a secure API and offers a free plan. Unlike Mailgun, no credit card is required when initially signing up for a free account.

  • Cost: For the first 30 days, free to send up to 40,000 emails. After that, it’s free to send up to 100 emails each day.
  • From Email Requirements: Works with any From Email, but we recommend using a domain-specific email for highest reliability.
  • Bottom Line: SendGrid is a super reliable option, and offers a free plan that will likely work for smaller businesses. Worth noting that it requires DNS access to properly complete setup.

Check out our step-by-step setup guide for the SendGrid mailer.

Sendinblue

Sendinblue

Sendinblue offers reliable email delivery services as well as a generous free plan. This mailer uses a secure API, and an added bonus is that you will not have to enter a credit card to complete setup (unless you decide you’d like a paid plan). If you already use Sendinblue for their email marketing services, then you can use that same account to set up this mailer.

  • Cost: Free for up to 300 emails per day. They also have a wide variety of paid plans with higher, monthly limits (please check out Sendinblue’s site for more details).
  • From Email Requirements: Works with any From Email, but we strongly recommend using a domain-specific email for highest reliability.
  • Bottom Line: Sendinblue is easy to get started (they have a good free account option, and no credit card required), and, most importantly, their services are reliable.

Check out our step-by-step setup guide for the Sendinblue mailer.

Gmail

google

The Gmail mailer uses Google’s API to securely improve email deliverability. It’s free and works with your existing Gmail or G Suite account. However, Google’s API tends to have more restrictions than the mailers listed above. For example, it has some strict server requirements (and if these requirements aren’t met on your site, you’d need to contact your site’s hosting provider to get those resolved).

  • Cost: Free. Please note, though, that Google simply won’t allow large numbers of emails to be sent with their API (you can check out more details on Google’s email limit page).
  • From Email Requirements: Works only with Gmail or G Suite email addresses. Further, only a single From Email can be used site-wide.
  • Bottom Line: Gmail’s API only offers a free service, so you don’t have to worry about getting charged at any point. However, if you do hit their limits then your emails will simply not be sent. Their API also tends to run into more issues than the other API-based mailer options, which can make it less reliable.

Check out our step-by-step setup guide for the Gmail mailer.

Outlook

microsoft

The Outlook mailer in WP Mail SMTP uses Microsoft’s Graph API to securely improve delivery of your site’s emails. A credit card is required to complete the account setup with Microsoft, however it’s free to use your account for better email delivery.

  • Cost: Free
  • From Email Requirements: Works only with Microsoft-based email addresses (example@outlook.com, example@live.com, and also Office 365 emails)
  • Bottom Line: Microsoft’s API is a secure option and free to use for email delivery. However, the set up is fairly involved, and this API tends to cause minor delays (a couple minutes at most) in email deliveries.

Check out our step-by-step setup guide for the Outlook mailer.

Amazon SES

aws

The Amazon SES mailer in WP Mail SMTP leverages Amazon’s API to successfully deliver emails sent out from your site. While Amazon allows this service to be used for free during your first year, after that pricing is based on use. A credit card is required to complete the account setup with Amazon, and your site must have an SSL certificate installed.

  • Cost: Free for the first year, then Amazon applies usage-based pricing.
  • From Email Requirements: Works with any domain-specific email address (ie example@yourdomain.com)
  • Bottom Line: Amazon SES is secure and free to get started (though you’ll need a credit card). The setup is fairly involved and, at one stage, requires approval from Amazon’s team. As a result, this mailer is only recommended for more technically advanced users.

Check out our step-by-step setup guide for the Amazon SES mailer.

Other SMTP

smtp

Other SMTP is the only mailer in WP Mail SMTP that does not use an API. Instead, it uses traditional SMTP (Simple Mail Transfer Protocol). This can be convenient in the short term, because the setup requires fewer steps.

However, this mailer tends to be less convenient long-term. For example, you’d need to edit your password setting any time you change your email’s password. It’s also more likely to run into server configuration issues (which you would need your webhost’s help to fix).

  • Cost: Free
  • From Email Requirements: Works with any email address, however you’ll need to use the same From Email site-wide.
  • Bottom Line: This should not be the first choice mailer option on any site, as it is less secure and less reliable than the other mailer options. For those sites where it’s needed and there are not server-related issues, though, the setup is often pretty quick.

Check out our step-by-step setup guide for the Other SMTP mailer.

Default (none)

Last, you may be wondering about the Default (none) option. The Default (none) option does not use SMTP and will not improve email delivery on your site.

So if you see this option in your WP Mail SMTP settings, be sure to choose one of the other mailer options instead. You can find links to step-by-step tutorials for each above.

That’s it! We’ve just shared an overview of all of the mailer options in WP Mail SMTP.

Would you prefer to let our team do the work of setting this all up for you? Be sure to check out our White Glove Setup option, where we do your mailer setup and testing.