Denys Cherkasov

The default <code>wp_mail()</code> function in WordPress can often be unreliable. Many hosting providers limit or poorly configure email sending, which leads to important notifications (like registrations, password resets, or WooCommerce orders) ending up in spam or not being delivered at all.
Cherkasov SMTP Mailer solves this problem by re-routing all your site’s outgoing emails through a professional SMTP server (such as Gmail, SendGrid, or any other mail service). This significantly increases the reliability and deliverability of your emails.
The plugin features a modern, intuitive interface, an advanced email log, and the ability to receive instant notifications about sending statuses in your Telegram.
<h3>Features</h3>
<ul>
<li>Reliable Delivery: Send emails through any SMTP server to avoid spam filters.</li>
<li>Easy Configuration: Quick presets for popular services (Gmail, Outlook, SendGrid) and flexible options for any other SMTP provider.</li>
<li>Email Log: Keeps a detailed log of all sent emails. View content, status, headers, and error messages.</li>
<li>Log Management: Search for emails, resend failed messages (one by one or all at once), and delete entries.</li>
<li>Telegram Notifications: Get instant messages in Telegram about successfully sent or failed emails.</li>
<li>Testing Tool: A built-in feature to send a test email to verify your settings and see a detailed debug log.</li>
<li>Security: Passwords and tokens are not displayed in the form after being saved and are transmitted securely.</li>
<li>Modern UI: A clean, responsive, and user-friendly interface built with modern web technologies.</li>
<li>Retention Policies: Configure automatic deletion of old log entries to keep your database clean.</li>
</ul>
<h3>Configuration</h3>
After activating the plugin, go to Settings > Cherkasov SMTP Mailer.
<h4>1. Main SMTP Settings</h4>
<ol>
<li>Mailer:
<ul>
<li>SMTP: Choose this option to send emails via an external server.</li>
<li>Default WP Mailer: Use your host’s standard mail function (not recommended).</li>
</ul>
</li>
<li>Providers: You can select a popular provider (Gmail, Outlook, SendGrid) to auto-fill the host and port fields.</li>
<li>SMTP Host, Port, and Encryption: Enter the details provided by your email service provider.</li>
<li>Authentication: In most cases, this toggle should be enabled.</li>
<li>SMTP Credentials: Enter the username (usually your email address) and password for your email account.
<ul>
<li>For Gmail/Google: If you have two-factor authentication enabled, you must create an “App Password” in your Google account’s security settings and use it here.</li>
</ul>
</li>
<li>Save Changes.</li>
</ol>
<h4>2. Sender Details</h4>
<ul>
<li>From Name: The name recipients will see.</li>
<li>From Email: The address emails will be sent from.</li>
<li>Force Sender: If enabled, all emails from your site (even from other plugins) will be sent using the specified From Name and From Email.</li>
</ul>
<h4>3. Telegram Notifications</h4>
<ol>
<li>Click the “Telegram Notifications” button.</li>
<li>Enable the “Enable Telegram Notifications” option.</li>
<li>Bot Token: Create a new bot by talking to <a href="https://t.me/botfather" rel="nofollow ugc"><code>@BotFather</code></a> on Telegram. It will provide you with a unique token. Paste it here.</li>
<li>Chat ID: Talk to the <a href="https://t.me/userinfobot" rel="nofollow ugc"><code>@userinfobot</code></a> and click “Start.” It will send you your unique ID. Paste it here.</li>
<li>Choose which events you want to be notified about (failed and/or successful sends).</li>
<li>Save the settings and click “Send Test” to verify.</li>
</ol>
<h3>Third-Party Services</h3>
This plugin uses the Telegram API to send notifications about the status of sent emails. This functionality is optional and only activated if you enable it in the settings and provide your own Telegram Bot Token and Chat ID.
<ul>
<li>Service: Telegram Bot API</li>
<li>Data Sent: When enabled, the plugin sends the recipient’s email address, email subject, your site’s URL, and the sending status (success or failure) to the Telegram API to be delivered to your specified chat.</li>
<li>Terms of Service: https://telegram.org/tos</li>
<li>Privacy Policy: https://telegram.org/privacy</li>
</ul>

Cherkasov SMTP Mailer

A reliable SMTP plugin for WordPress that ensures email delivery with logging and Telegram notifications.

Nicolas Verlhiac

<h3>Add Mail SMTP settings for WordPress</h3>
Looking to modify the SMTP on your WordPress site? 
Our Custom SMTP solution offers you this possibility, allowing you to easily change your WordPress SMTP settings, ensuring your emails consistently land in the recipient’s inbox.
Custom SMTP solves your email deliverability problems by reconfiguring WordPress to use a proper SMTP provider when sending emails.
What’s more, our intuitive settings page and comprehensive documentation will guide you through the process, making the task of modifying your SMTP settings easier than ever.
Custom SMTP is a free tool, packed with all the essential features you need to send your WordPress emails with absolute confidence!
Built for modern WordPress: WordPress 7.0 ready, PHPMailer 7.0.2 compatible, stateless / cloud-ready (Docker, Kubernetes), and fully translated in English and French.
<h3>Amazon SES API — keyless sending with IAM roles</h3>
Running WordPress on AWS (ECS Fargate, EC2, App Runner)? Custom SMTP can send through the Amazon SES API authenticated entirely by your container or instance IAM role — with no access keys, no secret keys, and no SMTP credentials stored anywhere. The plugin relies on the AWS default credential chain (the ECS task role / EC2 instance role), so your secrets never live in the database or the settings page.
This is the cleanest, most secure way to send from a containerized, 12-factor WordPress:
<ul>
<li>Zero stored secrets — authentication comes from the IAM role attached to the task/instance, not from keys pasted into wp-admin.</li>
<li>Full message fidelity — HTML, attachments, CC/BCC, Reply-To and custom headers are preserved (the message is sent as raw MIME); BCC recipients stay hidden.</li>
<li>SES Configuration Sets — optional, for bounce/complaint tracking and CloudWatch metrics.</li>
<li>Environment-driven — region, sender address and configuration set can be injected as environment variables / PHP constants (<code>SES_REGION</code> / <code>AWS_REGION</code>, <code>SES_FROM_EMAIL</code>, <code>SES_CONFIG_SET</code>), so the same image ships across environments without touching the database.</li>
<li>No extra dependency required — works whether or not the AWS SDK for PHP is present; when it isn’t, a built-in, dependency-free signed API client is used.</li>
<li>One-click test — send a test email and get back the SES MessageId.</li>
</ul>
<h3>Config-as-code & Multisite (immutable deployments)</h3>
For immutable Docker images, <code>DISALLOW_FILE_MODS</code> setups and large networks, every setting can be forced from the environment — no database writes at deploy time:
<ul>
<li>Any setting via a constant or env variable — define <code>CUSTOM_SMTP_<SETTING></code> (e.g. <code>CUSTOM_SMTP_MAILER_TYPE=ses_api</code>, <code>CUSTOM_SMTP_HOST</code>, <code>CUSTOM_SMTP_LOG_RETENTION</code>) and it overrides the saved value everywhere. The Amazon SES shortcuts (<code>SES_REGION</code> / <code>AWS_REGION</code>, <code>SES_FROM_EMAIL</code>, <code>SES_CONFIG_SET</code>) keep working too.</li>
<li>Activate a mailer network-wide with one variable — set <code>CUSTOM_SMTP_MAILER_TYPE=ses_api</code> in the container and every site uses Amazon SES, with zero per-site configuration and no custom <code>option_*</code> filter.</li>
<li>Multisite network settings — on a network, settings are read from the network-wide option (<code>get_site_option</code>) beneath any per-site option, so one configuration can apply to the whole network.</li>
<li>Visible in wp-admin — any field supplied by the environment is shown read-only with a “from <code>VARIABLE</code>” badge, so admins see exactly what the platform controls.</li>
</ul>
<h3>Built-in Email Logging</h3>
Never wonder if your emails were sent again. Custom SMTP automatically logs every email sent from your WordPress site – including WooCommerce order notifications, contact form submissions, and password resets. Preview email content directly in wp-admin, debug delivery issues with detailed error messages, and export logs for compliance.
<h3>Configuration Options</h3>
You can set the following options:
<ul>
<li>From Name & Email – Specify the sender name and email address for all outgoing emails</li>
<li>SMTP Host – Your email provider’s server (e.g., smtp.gmail.com)</li>
<li>SMTP Port – Common ports: 587 (TLS), 465 (SSL), 25 (None)</li>
<li>Encryption – Choose between None, SSL, or TLS</li>
<li>Authentication – Enable/disable SMTP authentication for relay servers</li>
<li>Username & Password – Your SMTP credentials (password stored encrypted)</li>
<li>Provider Presets – One-click configuration for Gmail, Outlook, iCloud, SendGrid, AWS SES, and more</li>
<li>Amazon SES API (IAM role) – Send through the Amazon SES API with no stored credentials, authenticated by your AWS task/instance role</li>
</ul>
<h3>Key Features</h3>
SMTP Configuration 
* Configure any SMTP server (Gmail, Outlook, SendGrid, Mailgun, AWS SES, etc.) 
* Support for SSL/TLS encryption 
* Optional SMTP authentication for relay servers 
* Test connection without sending emails 
* Send test emails to verify configuration
Amazon SES API (keyless, IAM role) 
* Send via the Amazon SESv2 API authenticated by your AWS IAM role — no access keys or SMTP credentials stored 
* Ideal for AWS ECS/Fargate, EC2 and other containerized, stateless deployments 
* Preserves HTML, attachments, CC/BCC, Reply-To and custom headers (raw MIME) 
* Optional SES Configuration Set for bounce/complaint/CloudWatch tracking 
* Region, sender and configuration set configurable via environment variables or constants 
* Works with or without the AWS SDK for PHP (built-in signed API client fallback) 
* “Send Test Email” returns the SES MessageId
Email Logging & Debugging 
* Zero configuration – Logging works out of the box 
* Track all emails sent from WordPress, WooCommerce, Contact Form 7, and any plugin 
* View delivery status (sent/failed) with detailed error messages 
* Debug wp_mail errors easily – See exactly why emails fail 
* Resend failed emails – Re-send a failed message straight from the logs after fixing your configuration 
* Store email headers for advanced troubleshooting 
* Search by recipient, subject, or status 
* Filter by date range (Today, 7 days, 30 days) 
* Export logs to CSV for reporting and compliance
Email Preview & Content 
* Preview email body directly from wp-admin – No need to send test emails 
* View HTML source code of any logged email 
* Outlook-style sidebar for quick preview 
* Download any email as HTML file for archiving 
* Optional content storage (disabled by default for privacy)
Deliverability 
* Cooperates with the automatic Envelope-From / Return-Path behavior introduced in WordPress 6.9 — improves SPF, DKIM and DMARC alignment on strict hosts (AWS SES, Postmark, etc.) 
* PHPMailer 7.0.2 compatible (the version bundled in WordPress 7.0) 
* UTF-8 and emoji handled end-to-end in subjects, bodies, and headers
Privacy & GDPR-friendly 
* SMTP password encrypted at rest (AES-256-CBC) 
* Configurable log retention with automatic purge (30 days by default) 
* Email content storage can be disabled in one click from the settings 
* Email preview rendered in a sandboxed iframe — no JavaScript execution from logged emails 
* All data stays in your WordPress database — no third-party calls
Security 
* SMTP password encrypted in database (AES-256-CBC) 
* All admin actions protected with nonces 
* Capability checks on all operations
Stateless & Cloud-Ready 
* Fully compatible with stateless WordPress hosting (containers, Kubernetes, AWS ECS/Fargate, etc.) 
* Works with Bedrock, Trellis, and other modern WordPress stacks 
* Zero filesystem writes – all data stored in the database 
* No shared storage (EFS/NFS) required between instances 
* Safe to run on read-only filesystems
AI & Workflow Integration (WordPress 6.9+) 
* <code>custom-smtp/connection-health</code> — read the current SMTP state (configured, host/port/encryption/auth, log retention) from any tool 
* <code>custom-smtp/send-test-email</code> — trigger a test email through your configured SMTP server 
* Compatible with MCP-enabled AI assistants, automation tools (n8n, Make), dashboards, and other plugins via the WordPress Abilities API 
* Protected by capability checks (<code>manage_options</code>) — same security boundary as the wp-admin interface

Custom SMTP: Email Deliverability – FREE & Easy-to-use

Effortlessly configure WordPress SMTP and monitor all sent emails. Built-in email logging with preview, error debugging, and WooCommerce support.

Cherkasov SMTP Mailer vs Custom SMTP: Email Deliverability – FREE & Easy-to-use