Complete in the free plugin
Fallback, retries, the email log, alerts and every native connection are in the free plugin, with no limit on connections and no licence check.
The WordPress SMTP plugin built for the day your provider says no
Most SMTP plugins send your email. BooleanSMTP also plans for when sending fails: a fallback, retries on your other connections, a record of every attempt, and an alert when nothing works.
A backup plan for every email. Not an upgrade.
When your provider refuses a message, BooleanSMTP tries your fallback connection straight away. With Retry on other connections on, as it is by default, the message then gets up to 2 more attempts, after about 1 and 5 minutes. Only then is it logged as Failed, and you hear about it on Slack, Discord, or Telegram.
Follow a failed sendSix more reasons. Each one checked against the plugin.
Native where it matters
Gmail, Microsoft 365, and Amazon SES have their own connections, over their APIs, with OAuth sign-in for Google and Microsoft. Everything else works over SMTP.
Every email on the record
Search, filter and resend from a log that keeps the provider’s exact error, in your own database.
Trusted with your keys
Credentials are encrypted with AES-256-CBC and HMAC-SHA-256, or kept in wp-config.php. The free plugin collects no usage data and never phones home.
Switching without risk
Import connections and the email log from 6 other SMTP plugins. They arrive as inactive drafts, so nothing changes until you have tested them.
Made for people who run WordPress
wp-config.php constants, WP-CLI commands and public hooks, so every client site can be set up the same way.
How it compares. Free versions, side by side.
What each plugin’s own WordPress.org description says its free version includes. Read on September 25, 2026; plugins change, so check their pages too.
| Feature | BooleanSMTP | FluentSMTP | WP Mail SMTP | Post SMTP | Easy WP SMTP | SureMail | GoSMTP |
|---|---|---|---|---|---|---|---|
| Email log | Free | Free | Pro | Free | Pro | Free | Pro |
| Backup connection when the main one fails | Free | Free | Pro | Free | Pro | Free | Free |
| Automatic retries after a failure | Free | Not listed | Pro | Pro | Pro | Free | Not listed |
| Failure alerts in Slack, Discord or Telegram | FreeAll three | FreeAll three, and Pushover | Pro | FreeSlack | Pro | FreeThrough SureTriggers | Pro |
| Microsoft 365 over its API | Free | Free | Pro | Pro | Pro | Not listed | Pro |
| Amazon SES | Free | Free | Pro | Pro | Pro | Free | Pro |
“Pro” means the plugin’s description names the feature as part of its paid version; “—” means the description does not mention it. Where others go further: FluentSMTP also sends alerts to Pushover, and several plugins connect to SendGrid, Mailgun and other services over their APIs, which BooleanSMTP reaches over SMTP until its dedicated connections ship.
“I have operated private email infrastructure that handled up to 30 million emails a day. That experience taught me that email delivery is more than sending a message.”
Before you choose
Developers: every constant, command and hook is on developers.booleansmtp.com.
Is BooleanSMTP really free?
Yes. The plugin is free and open source (GPLv2 or later), with no limit on connections and no licence check. BooleanSMTP Pro is coming later with routing rules, analytics and more; the free plugin stays complete on its own.
I use one of the plugins in the table. Can I move without breaking anything?
Yes. BooleanSMTP imports connections and the email log from FluentSMTP, WP Mail SMTP, Post SMTP, Easy WP SMTP, SureMail, and GoSMTP. They arrive switched off, so your site keeps sending through the old plugin until you have tested the new setup and deactivated it.
How was the comparison made?
From each plugin’s own description on WordPress.org, read on September 25, 2026, for its free version. “Pro” means the description names the feature as paid; a dash means the description does not mention it. Plugins change, so check their pages too.