FluentSMTP is WPManageNinja’s WordPress mailer plugin. It replaces WordPress’s default wp_mail() with authenticated SMTP or a provider API, the same job WP Mail SMTP does. The structural difference between the two is the business model. FluentSMTP has no Pro tier. The features WP Mail SMTP charges $99 a year for, including email logging, fallback connections, conditional routing, and failure alerts to Slack and Discord, ship in the free FluentSMTP plugin.
The plugin is developed by WPManageNinja LLC, the same team behind Fluent Forms, FluentCRM, Fluent Support, and Ninja Tables. The wp.org listing reports 600,000+ active installs at a 4.8 rating, current version 2.2.95 (released December 2025), tested up to WordPress 6.9.4. The vendor’s stated position is that the plugin “is free and will always be free”, and the public GitHub repository at WPManageNinja/fluent-smtp backs that up: there is no paid edition.
The short recommendation: FluentSMTP is the right default for a WordPress site that wants email logging, a fallback mailer, and conditional routing without paying for them. WP Mail SMTP remains the recommendation when the setup wizard, the Awesome Motive support contract, or the broader free mailer catalogue matters more than the absence of a $99 annual line item.
What it includes
Every feature is in the free plugin. The list, in the order an operator typically reaches for them:
- Mailer integrations for Amazon SES, Gmail / Google Workspace OAuth, Microsoft 365 / Outlook OAuth, SendGrid, Mailgun, Postmark, Brevo, SparkPost, SMTP2GO, Elastic Email, Zoho ZeptoMail, and Pepipost, plus a generic SMTP option for any provider. Two of those, Amazon SES and Microsoft 365 / Outlook OAuth, are gated behind WP Mail SMTP Pro; FluentSMTP exposes them at the free tier.
- Multiple connections with per-sender routing. Configure several mailers in one install and route by from-address. A common pattern: transactional mail from
noreply@through Postmark, marketing mail fromnews@through SendGrid, administrative mail through a generic SMTP relay. - Fallback connection. If the primary mailer fails, FluentSMTP retries through a configured fallback. The behaviour is closer to “second try via a different vendor” than full queueing; there is no Action Scheduler queue in the plugin.
- Email logging. Every send is recorded with recipient, subject, status, and timestamp. Failed sends can be retried from the log. Logging is the single feature most operators reach for after the initial mailer configuration is working, and it is the one WP Mail SMTP gates behind Pro.
- Failure notifications to email, Slack, Discord, or Telegram. Configurable per connection.
- OAuth 2.0 for Gmail / Google Workspace and Microsoft 365 / Outlook, with no app passwords required. See the Google OAuth credentials walkthrough for the Gmail setup steps.
- One-click migration from WP Mail SMTP. The plugin reads an existing WP Mail SMTP configuration and imports it.
- Test email from the settings page.
The admin interface is a Vue.js single-page application, which makes it visibly different from the traditional PHP-rendered settings screens that dominate the category. The practical effect is faster navigation between tabs; the configuration model itself is the same.
What it does not include
A short list, because what is missing is mostly the surrounding paid-tier infrastructure rather than feature gaps:
- No setup wizard of comparable depth to WP Mail SMTP’s. The configuration flow is direct (choose a connection, enter credentials, send a test) rather than a guided wizard. Operators comfortable with SMTP configuration will not notice; a first-time user configuring Gmail OAuth on WordPress will find WP Mail SMTP’s onboarding more forgiving.
- No paid support contract. Support is through the
wordpress.org plugin forum and the WPManageNinja community. Response is best-effort; there is no SLA. - No background queue. Email is sent in real time. Sites that send mail in bursts large enough to require backgrounding (thousands of messages per request) will hit the same PHP timeout issues here that they would on any non-queueing mailer plugin; the answer is provider-side processing, not the plugin.
- A slightly narrower native-provider list than WP Mail SMTP. WP Mail SMTP’s free version exposes more named mailers (SendLayer, Mailjet, Resend, Mandrill, MailerSend among them) than FluentSMTP does. Sites that specifically want one of those without falling back to generic SMTP credentials will prefer WP Mail SMTP.
The “always free” question
A plugin that gives away the feature set its largest competitor charges $99 a year for invites a reasonable question: how is this sustainable, and what is the catch?
WPManageNinja sells a paid product portfolio (Fluent Forms Pro, FluentCRM, Fluent Support, FluentBooking, Ninja Tables Pro), and FluentSMTP functions as a no-friction entry point into that ecosystem. The plugin is not directly monetised; the brand value it produces feeds the rest of the suite. The same playbook explains why FluentCRM ships the email-marketing automation that mailer plugins charge for, and why Fluent Forms ships the conditional logic that the leading forms plugin charges for. The product strategy is to be the free option in every category WPManageNinja competes in, and to convert on the paid products one tier up.
The catch, for a WordPress site that is not interested in any other WPManageNinja product, is functionally none. The plugin is GPL-compatible, open source, hosted on the wordpress.org repository, and developed in public on GitHub. There is no admin-area upsell because there is nothing to upsell the plugin to. The one mild push, a “WP Manage Ninja” branded link in the settings sidebar that surfaces the rest of the product family, is easily ignored.
Assessment
FluentSMTP is nanoPost’s recommendation for WordPress sites that want a mailer plugin with logging, routing, fallback, and OAuth without paying for them. The free feature parity with WP Mail SMTP Pro is real and reader-relevant: for an operator running a single site, choosing FluentSMTP saves $99 a year on renewal and removes the upsell pressure that is the most common complaint about WP Mail SMTP’s admin area.
The cases where WP Mail SMTP is the better default are specific and worth naming. Agencies configuring SMTP across dozens of client sites benefit from WP Mail SMTP’s setup wizard and broader free mailer catalogue. Sites already on WPForms Pro or otherwise inside the Awesome Motive product family get a single-vendor support contact by staying within it. Operators who want a paid support SLA on their mailer plugin have one available with WP Mail SMTP Pro and do not with FluentSMTP. The free-versus-paid distinction is not a quality distinction; both plugins work, and both are maintained.
Post SMTP remains worth considering specifically for operators who want push-notification alerts on mail failure to a phone app, which neither FluentSMTP nor WP Mail SMTP provides.
For most WordPress sites, FluentSMTP is the answer to “I want what WP Mail SMTP Pro does without paying for it”.
Plugin data verified June 2026 against wordpress.org/plugins/fluent-smtp, 
fluentsmtp.com, and the 
WPManageNinja/fluent-smtp GitHub repository. Tested against version 2.2.95.