Super Duper Plugins

<p><strong>Super Duper SMTP Mail Bridge</strong> replaces the unreliable WordPress PHP mail function with a properly authenticated SMTP connection. Emails reach inboxes instead of spam folders or the void.</p>
<p>🇨🇭🇩🇪🇦🇹 <em>Hinweis für DACH-Nutzer: Plugin und Support sind auf Deutsch (Schweiz/Deutschland/Österreich) verfügbar. Alle Texte und Einstellungen sind vollständig auf Deutsch übersetzt.</em></p>
<p>Unlike other SMTP plugins, this one gives you <strong>everything for free</strong> – no feature gates, no “upgrade to Pro” nags, no premium tiers. Every feature listed below works right out of the box.</p>
<h4>Why choose this plugin over the big names?</h4>
<p>Most popular SMTP plugins either lock essential features behind a paywall or are bloated with dozens of API integrations you don’t need. Here’s what makes Super Duper SMTP Mail Bridge different:</p>
<p><strong>🛡️ Backup SMTP with Automatic Failover</strong> — WP Mail SMTP charges $49+/year for this. FluentSMTP and Post SMTP offer fallback, but our implementation automatically logs each failover event separately so you can see exactly when and why your primary server failed.</p>
<p><strong>⏱️ Built-in Rate Limiting</strong> — No other free SMTP plugin offers this. Protect your domain reputation when a contact form gets spammed or a plugin goes rogue. Set limits per minute, hour, or day. Blocked emails are logged with a clear “Blocked” status.</p>
<p><strong>🌐 Domain Control (Whitelist & Blacklist)</strong> — Block disposable email domains (tempmail.com, guerrillamail.com) or restrict sending to specific recipient domains only. No other free SMTP plugin has both whitelist AND blacklist for recipient domains.</p>
<p><strong>🔐 AES-256-CBC Password Encryption</strong> — Your SMTP password is encrypted before it’s stored in the database. Most free SMTP plugins store credentials in plain text or use simple base64 encoding.</p>
<p><strong>📋 Full Email Log with HTML Preview</strong> — View the actual rendered email in an iframe preview or switch to source code view. Filter by status (Success, Failed, Blocked, Failover). WP Mail SMTP charges for email logging. We include it free, with content.</p>
<p><strong>🔧 SMTP Debug Transcript</strong> — Enable debug mode and get the complete SMTP server conversation logged for each email. Essential for troubleshooting – most plugins don’t offer this at all, or charge for it.</p>
<p><strong>⚠️ Smart Admin Notifications</strong> — Get notified by email when failures exceed your threshold. Includes the last error details, recipient, and subject. Built-in loop prevention ensures the notification itself doesn’t trigger more notifications.</p>
<p><strong>👁️ BCC Monitoring & GDPR/DSGVO Compliance</strong> — Automatically BCC all outgoing emails to one or more monitoring addresses. Combined with the email log, this provides legally verifiable proof that an email was actually sent – essential for GDPR (DSGVO) compliance. If a data subject ever disputes whether they received a notification, password reset, or consent confirmation, you have both the log entry and an independent BCC copy as evidence. No other free SMTP plugin offers this level of compliance-ready email auditing.</p>
<p><strong>🚫 Zero Bloat</strong> — No setup wizards, no upsell banners, no affiliate links to email services, no tracking. Just a clean settings page, your SMTP config, and a log. Under 50 KB total plugin size.</p>
<h4>Complete Feature List</h4>
<ul>
<li>SMTP configuration (host, port, TLS/SSL, authentication)</li>
<li>Configurable connection timeout (5–120 seconds)</li>
<li>Custom sender name and email address</li>
<li>Allowed sender domain validation</li>
<li>Backup SMTP server with automatic failover</li>
<li>Rate limiting (per minute, hour, or day)</li>
<li>BCC monitoring to one or more addresses</li>
<li>Recipient domain whitelist (only send to these)</li>
<li>Recipient domain blacklist (never send to these)</li>
<li>Admin error notification with configurable threshold</li>
<li>AES-256-CBC password encryption</li>
<li>Complete email log with status, headers, and error messages</li>
<li>HTML email preview (rendered) and source code view</li>
<li>SMTP debug transcript logging</li>
<li>Test email function directly from admin</li>
<li>Automatic log cleanup after configurable number of days</li>
<li>Clean uninstall – removes all data</li>
<li>Translations: German (CH/DE/AT), English, French, Spanish, Italian, Dutch</li>
</ul>
<h4>Feature Comparison</h4>
<p>Here is how Super Duper SMTP Mail Bridge compares to the most popular SMTP plugins, feature by feature.</p>
<p>Legend: ✅ = included for free · 🔒 = paid / Pro only · ❌ = not available</p>
<p><strong>Super Duper SMTP Mail Bridge (this plugin)</strong></p>
<ul>
<li>SMTP configuration: ✅</li>
<li>Email logging: ✅</li>
<li>Email content stored in log: ✅</li>
<li>Backup SMTP with automatic failover: ✅</li>
<li>Rate limiting (per minute / hour / day): ✅</li>
<li>Recipient domain whitelist: ✅</li>
<li>Recipient domain blacklist: ✅</li>
<li>BCC monitoring (GDPR/DSGVO proof): ✅</li>
<li>Strong password encryption (AES-256-CBC): ✅</li>
<li>SMTP debug transcript: ✅</li>
<li>Admin error alerts (failure threshold): ✅</li>
<li>Allowed sender domain validation: ✅</li>
<li>No ads / upsell in the admin: ✅</li>
</ul>
<p><strong>WP Mail SMTP</strong></p>
<ul>
<li>SMTP configuration: ✅</li>
<li>Email logging: 🔒</li>
<li>Email content stored in log: 🔒</li>
<li>Backup SMTP with automatic failover: 🔒</li>
<li>Rate limiting (per minute / hour / day): ❌</li>
<li>Recipient domain whitelist: ❌</li>
<li>Recipient domain blacklist: ❌</li>
<li>BCC monitoring (GDPR/DSGVO proof): ❌</li>
<li>Strong password encryption (AES-256-CBC): ❌</li>
<li>SMTP debug transcript: ❌</li>
<li>Admin error alerts (failure threshold): 🔒</li>
<li>Allowed sender domain validation: ❌</li>
<li>No ads / upsell in the admin: ❌</li>
</ul>
<p><strong>FluentSMTP</strong></p>
<ul>
<li>SMTP configuration: ✅</li>
<li>Email logging: ✅</li>
<li>Email content stored in log: ✅</li>
<li>Backup SMTP with automatic failover: ✅</li>
<li>Rate limiting (per minute / hour / day): ❌</li>
<li>Recipient domain whitelist: ❌</li>
<li>Recipient domain blacklist: ❌</li>
<li>BCC monitoring (GDPR/DSGVO proof): ❌</li>
<li>Strong password encryption (AES-256-CBC): ❌</li>
<li>SMTP debug transcript: ❌</li>
<li>Admin error alerts (failure threshold): ✅</li>
<li>Allowed sender domain validation: ❌</li>
<li>No ads / upsell in the admin: ✅</li>
</ul>
<p><strong>Post SMTP</strong></p>
<ul>
<li>SMTP configuration: ✅</li>
<li>Email logging: ✅</li>
<li>Email content stored in log: ✅</li>
<li>Backup SMTP with automatic failover: ✅</li>
<li>Rate limiting (per minute / hour / day): ❌</li>
<li>Recipient domain whitelist: ❌</li>
<li>Recipient domain blacklist: ❌</li>
<li>BCC monitoring (GDPR/DSGVO proof): ❌</li>
<li>Strong password encryption (AES-256-CBC): ❌</li>
<li>SMTP debug transcript: ✅</li>
<li>Admin error alerts (failure threshold): ✅</li>
<li>Allowed sender domain validation: ❌</li>
<li>No ads / upsell in the admin: ❌</li>
</ul>
<p><strong>YaySMTP</strong></p>
<ul>
<li>SMTP configuration: ✅</li>
<li>Email logging: ✅</li>
<li>Email content stored in log: ✅</li>
<li>Backup SMTP with automatic failover: ✅</li>
<li>Rate limiting (per minute / hour / day): ❌</li>
<li>Recipient domain whitelist: ❌</li>
<li>Recipient domain blacklist: ❌</li>
<li>BCC monitoring (GDPR/DSGVO proof): ❌</li>
<li>Strong password encryption (AES-256-CBC): ❌</li>
<li>SMTP debug transcript: ❌</li>
<li>Admin error alerts (failure threshold): ✅</li>
<li>Allowed sender domain validation: ❌</li>
<li>No ads / upsell in the admin: ❌</li>
</ul>
<p>Every feature in Super Duper SMTP Mail Bridge is included for free — no premium tier, no feature gates.</p>


Super Duper SMTP Mail Bridge

Reliable SMTP email delivery with backup failover, rate limiting, domain control, BCC monitoring, and full email log. 100% free.

Milan Petrovic

<p>The plugin adds a mail queue system that can intercept all the emails sent through the <code>wp_mail</code> function, and depending on the predefined rules (number of recipients), sent the email into the queue, with each recipient getting their email. On top of that, the plugin can process all plain text emails and wrap them in the HTML, and send them as HTML, with options to customize the template and various other aspects.</p>
<h4>How the plugin works</h4>
<p>The central part of the plugin, called ‘Mailer,’ controls the process.</p>
<ul>
<li>Intercept every <code>wp_mail</code> call</li>
<li>If needed, wrap email in HTML</li>
<li>Determine the number of recipients</li>
<li>If eligible, add each recipient email into the queue</li>
</ul>
<p>Process of turning plain text into HTML emails, support all emails sent through wp_mail, even if they don’t end in the queue. This can turn all WordPress system emails (registration, password reset…) into HTML emails and you can choose between predefined HTML templates, or register own templates via filter.</p>
<p>Queue works through the CRON, as a background job, and you can configure how many emails to send in a batch, with the timeout setting to prevent PHP timeout breaking the sending process.</p>
<h4>Email Sending</h4>
<p>Emails are sent using PHPMailer built into WordPress. But, the plugin has additional options to control the queue sending process and the wp_mail sending process.</p>
<ul>
<li>Email sending engine based on PHPMailer class</li>
<li>PHPMailer options to use SMTP for sending emails</li>
<li>Customize email From for all emails passed through <code>wp_mail</code></li>
<li>Customize email From, Reply, and Sender for all emails sent through the queue</li>
</ul>
<h4>Email Logging</h4>
<p>The plugin includes an advanced email log.</p>
<ul>
<li>Custom database tables to store logs, made for performance</li>
<li>Store all relevant data for each email, including a list of attachments</li>
<li>Email log panel with filters for logged emails</li>
<li>Preview popup displaying all logged email details</li>
<li>Preview popup shows the full HTML email part preview</li>
<li>Retry sending any failed emails through the queue</li>
</ul>
<h4>Security related features</h4>
<p>The plugin will attempt to strip malicious content from intercepted email, and sanitize the email plain text before generating HTML version, with the option to control the scope of the HTML tags to allow. HTML from subject will be striped. Emails stored in the log will be additionally sanitized, and on display, email content will be again escaped or run through KSES to avoid issues.</p>
<h4>Other plugin features</h4>
<ul>
<li>Options to pause wp_mail and queue operations</li>
<li>Dashboard: an overview of the queue (including the last run) statistics</li>
<li>Dashboard: an overview of the overall mailer statistics</li>
<li>Dashboard: additional boxes with various other information</li>
<li>Automatic cleanup of all successfully sent and/or failed emails</li>
<li>Logging of the errors for each email send through the queue</li>
<li>Developers friendly with various actions and filters for extra control</li>
<li>Support for intercepting bbPress subscription notifications emails</li>
<li>Support for the BuddyPress mail system</li>
<li>Option to set BuddyPress to use WordPress wp_mail() function</li>
<li>Track email types from emails sent by WordPress, bbPress and more</li>
<li>Tools to test sending of emails and adding to the queue</li>
</ul>
<h4>Upgrade to GD Mail Queue Pro</h4>
<p>Pro version contains many more great features:</p>
<ul>
<li>REST API based email sending engines</li>
<li>REST API Engine: SendGrid</li>
<li>REST API Engine: Amazon Web Services SES (through free addon)</li>
<li>REST API Engine: Gmail (through free addon)</li>
<li>REST API Engine: Mailgun (through free addon)</li>
<li>REST API Engine: Mailjet (through free addon)</li>
<li>REST API Engine: SendInBlue (through free addon)</li>
<li>PHPMailer third-party SMTP services support</li>
<li>PHPMailer SMTP Service: Amazon Web Services SES</li>
<li>PHPMailer SMTP Service: Mailgun</li>
<li>PHPMailer SMTP Service: Mailjet</li>
<li>PHPMailer SMTP Service: Mandrill</li>
<li>PHPMailer SMTP Service: PostMark</li>
<li>PHPMailer SMTP Service: PepiPost</li>
<li>PHPMailer SMTP Service: SendGrid</li>
<li>PHPMailer SMTP Service: SendInBlue</li>
<li>PHPMailer SMTP Service: SendPulse</li>
<li>PHPMailer SMTP Service: SparkPost</li>
<li>Panel to show everything currently in queue</li>
<li>Email Notifications with daily and weekly statistics</li>
<li>Email Notifications with daily and weekly errors logged</li>
<li>Safe staging support with email redirection</li>
<li>HTMLfy support for uploading logos</li>
<li>Improved dashboard with various control buttons</li>
<li>Improved log with the email role-based filtering</li>
<li>Tool to preview HTML template</li>
</ul>
<p>With more features on the roadmap exclusively for the Pro version.</p>
<ul>
<li>More information about <a href="https://plugins.dev4press.com/gd-mail-queue/" rel="nofollow ugc">GD Mail Queue Pro</a></li>
<li>Compare <a href="https://plugins.dev4press.com/gd-mail-queue/articles/lite-vs-pro/" rel="nofollow ugc">Free vs. Pro Plugin</a></li>
</ul>
<h4>More Information and Support</h4>
<ul>
<li>More information about <a href="https://plugins.dev4press.com/gd-mail-queue/" rel="nofollow ugc">GD Mail Queue</a></li>
<li>Support and Knowledge Base for <a href="https://support.dev4press.com/kb/product/gd-mail-queue/" rel="nofollow ugc">GD Mail Queue</a></li>
</ul>
<h4>Important</h4>
<ul>
<li>The plugin only works with the default WordPress <code>wp_mail</code> function that uses the <code>PHPMailer</code> object.</li>
<li>The plugin doesn’t replace <code>wp_mail</code> or PHPMailer and uses default function and class built into WordPress.</li>
<li>It is not advisable to use this plugin and some other plugin that manipulates WordPress <code>PHPMailer</code> object.</li>
<li>Plugin doesn’t support plugins replacing the <code>wp_mail</code> function (Sendgrid, WP Offload SES, and similar).</li>
</ul>


GD Mail Queue

Great plugin. As a thank you, I translated it into Russian. Later I saw that the premium version has such a package. Let those who do not have the premium version use it

Good plugin

Great Plugin

Intercept emails sent with wp_mail() into flexible mail queue for sending emails, convert plain text emails to HTML, email log, and more.

Super Duper SMTP Mail Bridge vs GD Mail Queue