Frumbik

WordPress uses the PHP <code>mail()</code> function by default, which often results in emails being marked as spam or not delivered at all. Frumbik SMTP replaces the default mail function with authenticated SMTP or API-based email delivery through your chosen provider.
Connect Gmail, SendGrid, Amazon SES, or any SMTP server — and all emails WordPress sends will be properly authenticated, encrypted, and delivered.
<h4>Key Features</h4>
Frumbik SMTP provides the following capabilities, all included in the free version:
🔄 Automatic Failover — If your primary provider goes down, emails automatically route to your backup provider.
📊 Dashboard — Real-time delivery stats, success rates, and charts. See what is happening with your emails at a glance.
📋 Complete Email Log — Every email logged with status, timestamps, headers, and source plugin. Search, filter, resend, or export — all from one screen.
🔐 Strong Security — AES-256-CBC encryption for all credentials. Security scoring dashboard with actionable recommendations.
⚡ Background Queue — High-traffic site? Queue emails for async delivery so your pages load fast while emails send in the background.
🎯 Smart Routing — Route WooCommerce emails through SendGrid, contact forms through Mailgun, and newsletters through Amazon SES — all automatically.
<h4>9 Providers, One Plugin</h4>
Connect to any email service without installing separate add-ons:
<ul>
<li>Other SMTP — Any SMTP server (Gmail, Outlook, Yahoo, your hosting, custom servers)</li>
<li>SendGrid — Transactional email API by Twilio</li>
<li>Mailgun — Email API by Sinch</li>
<li>Postmark — Transactional email delivery by ActiveCampaign</li>
<li>Brevo (formerly Sendinblue) — Marketing and transactional email</li>
<li>SparkPost — Email delivery by MessageBird</li>
<li>Amazon SES — AWS Simple Email Service (v2 API with Signature v4)</li>
<li>Microsoft 365 / Outlook — Microsoft Graph API with OAuth 2.0</li>
<li>Gmail API — Google Gmail API with OAuth 2.0</li>
</ul>
All providers are included in the plugin.
<h4>Core Features</h4>
📨 Reliable Email Delivery
<ul>
<li>Replace WordPress’s unreliable <code>wp_mail()</code> with authenticated SMTP or native API connections</li>
<li>Supports TLS and SSL encryption protocols</li>
<li>Proper SPF, DKIM, and DMARC alignment through your provider</li>
<li>Works with any WordPress theme, plugin, or page builder</li>
</ul>
📋 Comprehensive Email Logging
<ul>
<li>Every outgoing email logged automatically — sent, failed, or queued</li>
<li>Full details: recipients, subject, body, headers, attachments, timestamps</li>
<li>Automatic source detection — know which plugin triggered each email</li>
<li>One-click resend for failed or bounced emails</li>
<li>CSV export with advanced search and filtering</li>
<li>Configurable log retention (auto-cleanup old logs)</li>
</ul>
🔄 Multi-Connection & Failover
<ul>
<li>Configure multiple mail providers simultaneously</li>
<li>Automatic failover — if Provider A fails, Provider B takes over instantly</li>
<li>No manual intervention needed. No lost emails during outages.</li>
<li>Connection health monitoring with success rate tracking</li>
</ul>
🎯 Smart Routing Rules
<ul>
<li>Route emails to different providers based on conditions:
<ul>
<li>Recipient email address or domain</li>
<li>Email subject containing specific keywords</li>
<li>The WordPress plugin that triggered the email</li>
</ul>
</li>
<li>Example: WooCommerce orders → SendGrid, contact forms → Mailgun</li>
<li>Priority ordering with drag-free interface</li>
</ul>
⚡ Email Queue (Async Sending)
<ul>
<li>Queue emails for background delivery via WP-Cron</li>
<li>Pages load faster — no waiting for SMTP connections during page loads</li>
<li>Failed emails automatically retried with exponential backoff</li>
<li>Configurable batch size and retry limits</li>
<li>Real-time queue dashboard with cancel/retry controls</li>
</ul>
🔔 Failure Notifications
<ul>
<li>Get alerted instantly when emails fail to send</li>
<li>4 notification channels: Email, Slack, Discord, Telegram</li>
<li>Per-event subscription — choose exactly which events trigger alerts</li>
<li>Notification history with delivery status tracking</li>
</ul>
🔐 Security
<ul>
<li>AES-256-CBC encryption for all stored credentials (passwords, API keys, OAuth tokens)</li>
<li>Security Score Dashboard — real-time security posture with actionable fix recommendations</li>
<li>Dedicated encryption key support via <code>wp-config.php</code></li>
<li>Rate limiting on all REST API endpoints</li>
<li>Six custom WordPress capabilities for role-based access control</li>
<li>Full audit log tracking every configuration change</li>
<li>CSRF protection, nonce verification, input sanitization throughout</li>
</ul>
🧙 Setup Wizard
<ul>
<li>Guided 7-step wizard for first-time configuration</li>
<li>Automatic import from WP Mail SMTP, Post SMTP, Fluent SMTP, and Easy WP SMTP</li>
<li>Provider presets with pre-filled configuration fields</li>
<li>Built-in connection test with real-time feedback</li>
</ul>
🛠️ Import / Export & Tools
<ul>
<li>Export your complete configuration as a JSON file (settings, connections, routing rules)</li>
<li>Import on another site to replicate your setup instantly</li>
<li>Debug Info page with system diagnostics for troubleshooting</li>
<li>Multisite-compatible import/export</li>
</ul>
🖥️ Modern Admin Interface
<ul>
<li>React-powered single-page application — fast and responsive</li>
<li>Real-time dashboard with delivery charts and statistics</li>
<li>Responsive design for desktop, tablet, and mobile</li>
<li>Built with WordPress accessibility standards (WCAG 2.1)</li>
<li>Full internationalization support (i18n-ready)</li>
</ul>
🌐 Multisite Ready
<ul>
<li>Full WordPress Multisite support out of the box</li>
<li>Network-wide or per-site configuration</li>
<li>Network admin management panel</li>
<li>Settings propagation across all network sites</li>
</ul>
<h4>For Developers</h4>
<ul>
<li>Hooks & Filters — 30+ action and filter hooks for complete customization</li>
<li>IoC Container — Laravel-inspired dependency injection container</li>
<li>PSR-4 Autoloading — Clean, namespaced codebase via Composer</li>
<li>REST API — Full REST API for headless or programmatic management</li>
<li>Extensible Providers — Add custom mail providers by implementing <code>MailProviderInterface</code></li>
<li>Strategy Pattern — Clean architecture with strategy, repository, and service provider patterns</li>
</ul>
<h3>External services</h3>
This plugin connects to third-party email delivery services and notification platforms to send emails and alerts on your behalf. No data is sent to any service unless you explicitly configure and enable that provider or notification channel in the plugin settings.
<h4>Gmail API (Google)</h4>
When configured as a mail provider, this plugin connects to the Gmail API to send emails using your Google account via OAuth 2.0.
<ul>
<li>Endpoints: <code>https://gmail.googleapis.com</code>, <code>https://accounts.google.com</code>, <code>https://oauth2.googleapis.com</code></li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), OAuth tokens for authentication</li>
<li>When: each time WordPress sends an email through this provider, and during OAuth authentication</li>
<li><a href="https://policies.google.com/privacy" rel="nofollow ugc">Google Privacy Policy</a></li>
<li><a href="https://policies.google.com/terms" rel="nofollow ugc">Google Terms of Service</a></li>
</ul>
<h4>Microsoft 365 / Outlook (Microsoft Graph API)</h4>
When configured as a mail provider, this plugin connects to the Microsoft Graph API to send emails using your Microsoft 365 or Outlook account via OAuth 2.0.
<ul>
<li>Endpoints: <code>https://graph.microsoft.com</code>, <code>https://login.microsoftonline.com</code></li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), OAuth tokens for authentication</li>
<li>When: each time WordPress sends an email through this provider, and during OAuth authentication</li>
<li><a href="https://privacy.microsoft.com/en-us/privacystatement" rel="nofollow ugc">Microsoft Privacy Statement</a></li>
<li><a href="https://www.microsoft.com/en-us/servicesagreement" rel="nofollow ugc">Microsoft Services Agreement</a></li>
</ul>
<h4>SendGrid (Twilio)</h4>
When configured as a mail provider, this plugin sends emails through the SendGrid API.
<ul>
<li>Endpoint: <code>https://api.sendgrid.com/v3</code></li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), API key for authentication</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://www.twilio.com/en-us/legal/privacy" rel="nofollow ugc">Twilio Privacy Policy</a></li>
<li><a href="https://www.twilio.com/en-us/legal/tos" rel="nofollow ugc">Twilio Terms of Service</a></li>
</ul>
<h4>Mailgun (Sinch)</h4>
When configured as a mail provider, this plugin sends emails through the Mailgun API.
<ul>
<li>Endpoints: <code>https://api.mailgun.net/v3</code> (US region) or <code>https://api.eu.mailgun.net/v3</code> (EU region)</li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), API key for authentication</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://www.mailgun.com/legal/privacy-policy/" rel="nofollow ugc">Mailgun Privacy Policy</a></li>
<li><a href="https://www.mailgun.com/legal/terms/" rel="nofollow ugc">Mailgun Terms of Service</a></li>
</ul>
<h4>Brevo (formerly Sendinblue)</h4>
When configured as a mail provider, this plugin sends emails through the Brevo API.
<ul>
<li>Endpoint: <code>https://api.brevo.com/v3</code></li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), API key for authentication</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://www.brevo.com/legal/privacypolicy/" rel="nofollow ugc">Brevo Privacy Policy</a></li>
<li><a href="https://www.brevo.com/legal/termsofuse/" rel="nofollow ugc">Brevo Terms of Use</a></li>
</ul>
<h4>SparkPost (MessageBird)</h4>
When configured as a mail provider, this plugin sends emails through the SparkPost API.
<ul>
<li>Endpoints: <code>https://api.sparkpost.com/api/v1</code> (US) or <code>https://api.eu.sparkpost.com/api/v1</code> (EU)</li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), API key for authentication</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://www.sparkpost.com/policies/privacy/" rel="nofollow ugc">SparkPost Privacy Policy</a></li>
<li><a href="https://www.sparkpost.com/policies/tou/" rel="nofollow ugc">SparkPost Terms of Use</a></li>
</ul>
<h4>Postmark (ActiveCampaign)</h4>
When configured as a mail provider, this plugin sends emails through the Postmark API.
<ul>
<li>Endpoint: <code>https://api.postmarkapp.com</code></li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), server API token for authentication</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://postmarkapp.com/privacy-policy" rel="nofollow ugc">Postmark Privacy Policy</a></li>
<li><a href="https://postmarkapp.com/terms-of-service" rel="nofollow ugc">Postmark Terms of Service</a></li>
</ul>
<h4>Amazon SES (Amazon Web Services)</h4>
When configured as a mail provider, this plugin sends emails through the Amazon SES v2 API using AWS Signature v4 authentication.
<ul>
<li>Endpoint: <code>https://email.{region}.amazonaws.com</code> (region depends on your configuration)</li>
<li>Data sent: email content (recipients, subject, body, headers, attachments), signed with AWS access key credentials</li>
<li>When: each time WordPress sends an email through this provider</li>
<li><a href="https://aws.amazon.com/privacy/" rel="nofollow ugc">AWS Privacy Notice</a></li>
<li><a href="https://aws.amazon.com/service-terms/" rel="nofollow ugc">AWS Service Terms</a></li>
</ul>
<h4>Telegram Bot API</h4>
When configured as a notification channel, this plugin sends failure alerts to a Telegram chat using the Telegram Bot API.
<ul>
<li>Endpoint: <code>https://api.telegram.org/bot{token}/sendMessage</code></li>
<li>Data sent: notification messages containing email failure details (recipient, subject, error message, timestamp)</li>
<li>When: each time a configured notification event occurs (e.g., email delivery failure)</li>
<li><a href="https://telegram.org/privacy" rel="nofollow ugc">Telegram Privacy Policy</a></li>
<li><a href="https://telegram.org/tos" rel="nofollow ugc">Telegram Terms of Service</a></li>
</ul>
<h4>Slack</h4>
When configured as a notification channel, this plugin sends failure alerts to a Slack channel using incoming webhooks.
<ul>
<li>Endpoint: user-configured Slack webhook URL (<code>https://hooks.slack.com/services/...</code>)</li>
<li>Data sent: notification messages containing email failure details (recipient, subject, error message, timestamp)</li>
<li>When: each time a configured notification event occurs (e.g., email delivery failure)</li>
<li><a href="https://slack.com/trust/privacy/privacy-policy" rel="nofollow ugc">Slack Privacy Policy</a></li>
<li><a href="https://slack.com/terms-of-service" rel="nofollow ugc">Slack Terms of Service</a></li>
</ul>
<h4>Discord</h4>
When configured as a notification channel, this plugin sends failure alerts to a Discord channel using webhooks.
<ul>
<li>Endpoint: user-configured Discord webhook URL (<code>https://discord.com/api/webhooks/...</code>)</li>
<li>Data sent: notification messages containing email failure details (recipient, subject, error message, timestamp)</li>
<li>When: each time a configured notification event occurs (e.g., email delivery failure)</li>
<li><a href="https://discord.com/privacy" rel="nofollow ugc">Discord Privacy Policy</a></li>
<li><a href="https://discord.com/terms" rel="nofollow ugc">Discord Terms of Service</a></li>
</ul>

Frumbik SMTP

Send WordPress emails via SMTP or API providers (SendGrid, SES, Gmail, M365) with smart routing, failover, email logging, and queue.

arianKhosravi

NorikDavtian

Overwrites the native wp_mail function and uses sendgrid servers to send emails.
For a complete list of SendGrid features visit <a href="http://sendgrid.com" rel="nofollow ugc">SendGrid</a>
Here is list of features provided by SendGrid
Save Time, Resources and Money
SendGrid helps you focus on your business without the cost and complexity of owning and maintaining an email infrastructure. SendGrid manages all of the technical details from scaling the infrastructure to ISP outreach and reputation monitoring to whitelist services and real time analytics. Save time, resources, and money by focusing your engineering resources on your business and leave the technical work to SendGrid.
Messages That Reach the Inbox
On average 20% of legitimate emails never reach the inbox. For your business, that means lower customer satisfaction, lost customers and less revenue. SendGrid offers world class deliverability expertise to make sure your emails get delivered. SendGrid handles ISP monitoring, DKIM, domain keys, SPF, feedback loops, whitelabeling, link customization and more. SendGrid even offers unique IP addresses so that you can maintain complete control of your own email reputation.
Integrate in Minutes, Not Weeks
Whether you’re sending transactional or marketing emails, SendGrid has an API to make custom integration a breeze. Choose from an SMTP API, Web API, Event API, and more. Or, integrate in merely minutes via a simple SMTP relay. You’ll be sending emails in no time.
Actionable, Real Time Analytics
Drive solid business decisions with precise analytics on your email campaigns. Easily categorize separate email campaigns and track statistics down to the email address. Track requests, delivered, bounces, repeat bounces, spam reports, repeat spam reports, invalid email requests, open tracking, unique open tracking, click tracking, unique click tracking, unsubscribe tracking and blocks. All stats are available via our website dashboard or customizable through our Event and/or Web APIs.
Help When You Need It
SendGrid offers support via phone or live chat during weekdays from 7am to 7pm (Mountain Time) with critical incident support available 24/7. Self-support is also available through extensive documentation, an online knowledge base, and an active support community at SendGrid.com
Incredibly Scalable Infrastructure
Whether you’re sending 100 emails or billions of emails per month, SendGrid’s infrastructure is ready to scale and meet the demand at any moment. SendGrid currently sends over 5 billion emails per month for tens of thousands of companies. We’re ready to make your scalability problems a thing of the past.

Big Mailer – SendGrid

Overwrites the native wp_mail function and uses sendgrid servers to send emails

Frumbik SMTP vs Big Mailer – SendGrid