Super Duper Plugins

Super Duper SMTP Mail Bridge replaces the unreliable WordPress PHP mail function with a properly authenticated SMTP connection. Emails reach inboxes instead of spam folders or the void.
🇨🇭🇩🇪🇦🇹 Hinweis für DACH-Nutzer: Plugin und Support sind auf Deutsch (Schweiz/Deutschland/Österreich) verfügbar. Alle Texte und Einstellungen sind vollständig auf Deutsch übersetzt.
Unlike other SMTP plugins, this one gives you everything for free – no feature gates, no “upgrade to Pro” nags, no premium tiers. Every feature listed below works right out of the box.
<h4>Why choose this plugin over the big names?</h4>
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:
🛡️ Backup SMTP with Automatic Failover — 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.
⏱️ Built-in Rate Limiting — 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.
🌐 Domain Control (Whitelist & Blacklist) — 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.
🔐 AES-256-CBC Password Encryption — 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.
📋 Full Email Log with HTML Preview — 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.
🔧 SMTP Debug Transcript — 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.
⚠️ Smart Admin Notifications — 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.
👁️ BCC Monitoring & GDPR/DSGVO Compliance — 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.
🚫 Zero Bloat — 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.
<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>
Here is how Super Duper SMTP Mail Bridge compares to the most popular SMTP plugins, feature by feature.
Legend: ✅ = included for free · 🔒 = paid / Pro only · ❌ = not available
Super Duper SMTP Mail Bridge (this plugin)
<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>
WP Mail SMTP
<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>
FluentSMTP
<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>
Post SMTP
<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>
YaySMTP
<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>
Every feature in Super Duper SMTP Mail Bridge is included for free — no premium tier, no feature gates.

Super Duper SMTP Mail Bridge

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

This plugin enhances the security and stability of your WordPress installation by delaying and controlling wp_mail() email submissions through a managed queue.
If your site exhibits unusual behavior, such as a spam bot repeatedly submitting forms, you will be alerted immediately and can optionally pause delivery automatically while you investigate.
<ul>
<li>Intercepts wp_mail() and places outgoing messages in a queue</li>
<li>Configure how many emails are sent and at what interval</li>
<li>Pause the queue without disabling the plugin completely</li>
<li>Log queued emails, sent emails, alerts, and queue events</li>
<li>Receive alerts when the queue grows unexpectedly</li>
<li>Optionally auto-pause the queue when an alert is triggered</li>
<li>Send selected queued emails immediately from the backend</li>
<li>Automatically prioritize WordPress password reset emails</li>
<li>Receive alerts when WordPress is unable to send emails</li>
</ul>

Mail Queue

Gain full control over your WordPress emails. Queue outgoing emails and get alerts when your site tries to send unusually high volumes.

Super Duper SMTP Mail Bridge vs Mail Queue