Custom Queued SMTP Mailer

Plugin Overview

The Custom SMTP Mailer (Bypassproof) ensures all WordPress and WooCommerce emails go out securely via your chosen SMTP server. Unlike standard mailers, it encrypts and stores credentials in config.php with read-only permissions. If file writing fails, it securely falls back to the database with key separation.
The plugin adds a Tools → Custom SMTP Mailer settings page for configuration, testing, and recovery. It also warns about conflicts with other mailer plugins to keep your delivery chain reliable.

Key Features

• Encrypted Credentials: Stored in config.php with read-only (400) permissions.
• Database Fallback: Encrypted fallback in custom DB table if file saving fails.
• Key Separation: Encryption key stored in WordPress options, separate from creds.
• Automatic Conflict Detection: Warns if other plugins hook into phpmailer_init or wp_mail.
• Specific Conflict Alerts: Detects WP Mail SMTP, Easy WP SMTP, and Post SMTP.
• Test Email Tool: Quickly verify your SMTP config from the Tools page.
• Auto “From” Override: Ensures consistent From/Reply-To headers across all emails.
• .htaccess Protection: Auto-adds deny rules for sensitive files.
• Bypass-Proof Delivery: Hooks late into WordPress, ensuring your SMTP settings win.
• WooCommerce Ready: Works out of the box with order emails and notifications.

How it Works and What to Expect

• Enter SMTP host, port, encryption, username, and password in the Tools page.
• Credentials are encrypted with Sodium (libsodium or sodium_compat) and written to config.php.
• If file saving fails, the plugin securely encrypts and stores them in the DB (sender_helper table).
• The plugin forces WordPress to always use your defined From / Reply-To, stripping out overrides.
• Only one mailer runs — it warns you if other plugins attempt to interfere.
• Expect reliable, secure, and consistent SMTP delivery, even under server permission issues.

Performance Overview

• Lightweight footprint: No overhead beyond a single Tools page and mail hooks.
• On-demand encryption: Uses Sodium only at save/read operations.
• Minimal queries: Credentials cached to reduce DB lookups.
• No front-end impact: Runs entirely in the admin + mail layer.

Requirements & Compatibility

• WordPress: 6.0 or higher
• PHP: 8.0 or higher
• PHP Extensions: Sodium (or bundled sodium_compat)
• WooCommerce: Optional, fully compatible
• Webserver: Apache recommended for .htaccess protection (works without it too)

Language Support

Available Languages:

• English
• Spanish
• French
• German
• Italian

Custom Language Files

The plugin supports custom translations. You can easily add your own .po and .mo files for any language, or use translation plugins like Polylang, WPML, and TranslatePress for dynamic translation of ALT texts.

License

The Custom SMTP Mailer is licensed under the Single Domain Licence:

• 1 license per domain.
• For more details, visit: LitePlugin License