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.

JWardee

Logging your mail will stop you from ever losing your emails again! This fast, lightweight plugin (under 140kb in size!) is also useful for debugging or backing up your messages.
Just install and activate then all of your contact form emails will be logged and saved to your DB with no additional configuration required.
View and manage all your form submissions through the default WordPress interface. An email failed to send? With a single click you can resend the backed up email.
Send emails out directly from the WordPress interface. Also includes support for attachments.
Immediately find out if your contact form submission was successfully sent.
<h3>Features</h3>
<ul>
<li>Zero setup required – just install and away you go</li>
<li>Minimalistic – no overbloated features you never use weighing your site down – under 140kb in size!</li>
<li>Bulk export emails to CSV for easy inclusion into Excel or any other program</li>
<li>Compose new emails with the WordPress controls you’re already familiar with</li>
<li>Resend your emails in bulk</li>
<li>Debugging – see exactly which file and code line was responsible for sending the email, along with any errors encountered</li>
<li>Manage what user permissions can see the logs</li>
<li>Routinely have your logs cleared out at a specified time – or keep them forever</li>
<li>Need to be notified when there’s a problem sending your mail? We’ve got hooks that allow you to do just that</li>
<li>Completely free</li>
</ul>
<h3>Hooks and actions</h3>
<ul>
<li><code>wp_mail_catcher_mail_success</code> is triggered when a message is sent and logged successfully. It has a single argument that is an array containing the log
<ul>
<li><code>id</code> related to the id in the <code>mail_catcher_logs</code> MySQL table</li>
<li><code>time</code> relative, readable time to when the log was saved</li>
<li><code>email_to</code> the email address(es) that the message was sent to</li>
<li><code>subject</code> the subject line of the message</li>
<li><code>message</code> the contents of the message</li>
<li><code>status</code> an integer depicting if the message was sent successfully or not (1 = sent successfully. 0 = sending failed)</li>
<li><code>error</code> the error that occurred – if any</li>
<li><code>backtrace_segment</code> a json_encoded object that shows which file and line the mail was initially triggered from</li>
<li><code>attachments</code> a list of any attachments that were sent along with the email</li>
<li><code>additional_headers</code> a list of any headers that were sent</li>
<li><code>attachment_file_paths</code> a list of the location of any attachments that were sent</li>
<li><code>timestamp</code> a unix timestamp of when the email was sent</li>
<li><code>is_html</code> a boolean, that will be true if the message is a html email and false if not</li>
<li><code>email_from</code> the from value of the email</li>
</ul>
</li>
<li><code>wp_mail_catcher_mail_failed</code> is triggered when a message failed to send and logged successfully. It has a single argument that is an array containing the log (same as the arguments for <code>wp_mail_catcher_mail_success</code>)</li>
<li><code>wp_mail_catcher_deletion_intervals</code> is a filter that should return an array where each key is an amount of time in seconds, and the value is the label. Used to determine when a message has expired and should be deleted</li>
<li><code>wp_mail_catcher_before_success_log_save</code> is a filter that is called just before a successful log is saved. It has a single argument that is the transformed log that will be saved – use this to alter the log before it’s saved. Returning <code>false</code> will stop the log from being saved. Also note that this is fired even when an email has errored, because all logs are initially saved as “successful” before being possibly updated with an error (if applicable). This is because of the way the <code>wp_mail</code> and <code>wp_mail_failed</code> are implemented in WordPress.
<ul>
<li><code>time</code> a unix timestamp of when the email was sent</li>
<li><code>email_to</code> the email address(es) that the message was sent to</li>
<li><code>subject</code> the subject line of the message</li>
<li><code>message</code> the contents of the message</li>
<li><code>backtrace_segment</code> an array that shows which file and line the mail was initially triggered from</li>
</ul>
</li>
<li><code>wp_mail_catcher_before_error_log_save</code>
<ul>
<li><code>time</code> a unix timestamp of when the email was sent</li>
<li><code>email_to</code> the email address(es) that the message was sent to</li>
<li><code>subject</code> the subject line of the message</li>
<li><code>message</code> the contents of the message</li>
<li><code>backtrace_segment</code> an array that shows which file and line the mail was initially triggered from</li>
<li><code>error</code> the error that occurred</li>
</ul>
</li>
</ul>

Mail logging – WP Mail Catcher


Works great. It needs a some adjustments though on mobile screens.


Works Great


Really well done thank you!Very useful debug function with the code that sent the email!


Keeps track of all emails sent


Works perfectly as expected, every single time, for years and years!


The Best!

just perfect!


simple and lightweight. with this you have the absolute control over what was successfully send. besides that you can also send a manual email from the dashboard. nice


Perfect companion for wp mail smtp or wpo365


This is a great extension, and does everything that you need of an email logging extension. 



Very useful for debugging purposes!


Easy to use, with no bloat.


tested it for a few weeks and it's very fine, lite and fast.



only one small proposal: option to redirect an email - some users input their email wrong and admins can see this and redirect to the correct email address (ex. @yhoo.com instead of yahoo.com)


perfect for mail logging and preview

Stop from ever losing your emails again! This fast, lightweight plugin (under 140kb in size!) is also useful for debugging or backing up your messages

Super Duper SMTP Mail Bridge vs Mail logging – WP Mail Catcher