150 lines
5.2 KiB
Text
150 lines
5.2 KiB
Text
=== SMTP (by ROBOTSTXT) Newsletter ===
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Contributors: robotstxt
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Tags: newsletter, smtp, email, bulk, queue, worker, amazonses, statistics
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Requires at least: 4.7
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Tested up to: 6.9
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Requires PHP: 7.2
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Stable tag: 2.2.0
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License: GPLv2 or later
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License URI: https://www.gnu.org/licenses/gpl-2.0.html
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Integrates ROBOTSTXT SMTP configuration with Newsletter plugin for reliable bulk email delivery with database-backed queue and external workers.
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== Description ==
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SMTP (by ROBOTSTXT) Newsletter connects your Newsletter plugin with ROBOTSTXT SMTP and Amazon SES plugins, providing **reliable, scalable bulk email delivery** through a database-backed queue system with external worker processes.
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= Key Features =
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* **Database Queue**: Persistent email queue survives server restarts and crashes
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* **External Workers**: CLI worker script for asynchronous processing independent of WordPress cron
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* **Parallel Processing**: Run multiple workers simultaneously for high-volume campaigns
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* **Automatic Retry**: Failed emails retry up to 3 times with exponential backoff
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* **Real-Time Statistics**: Monitor queue status and campaign performance
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* **Campaign Metrics**: Track speed, duration, success rate for each campaign
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* **Amazon SES Support**: Native integration with Amazon SES API
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* **Rate Limiting**: Respects ROBOTSTXT SMTP rate limits
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* **Scalable**: Handle campaigns of any size with parallel workers
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= Architecture =
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**Version 2.2.0 introduces a queue-based architecture:**
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* Newsletter campaigns are queued to database instead of sent immediately
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* External worker processes pick up queued emails and send them via wp_mail()
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* Statistics are tracked and preserved even after queue cleanup
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* Multiple workers can run in parallel for high-volume sending
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= Performance & Reliability =
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**Reliability:**
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* Emails persisted to database - no data loss on crashes
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* Automatic retry with exponential backoff (5min → 15min → 30min)
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* Stale lock recovery prevents stuck emails
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**Scalability:**
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* Support for 10+ parallel workers
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* Process 10,000+ emails per hour with proper worker setup
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* Campaign statistics track actual sending speed
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**Monitoring:**
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* Real-time queue status (pending, processing, sent, failed)
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* Campaign metrics (start time, duration, speed, success rate)
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* Detailed email queue view in admin
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= Requirements =
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* Newsletter plugin 9.0.0 or higher
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* ROBOTSTXT SMTP plugin 2.0.0 or higher
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* (Optional) ROBOTSTXT SMTP Amazon SES plugin 1.0.0 or higher
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* CLI access for worker setup (cron or process supervisor)
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= Setup =
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**Installation:**
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1. Install and activate the plugin
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2. Go to Newsletter → SMTP (by ROBOTSTXT)
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3. Enable integration and configure batch size
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**Worker Setup (Required):**
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Set up a cron job or process supervisor to run the worker:
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`* * * * * php /path/to/wp-content/plugins/robotstxt-smtp-newsletter/worker.php 10 "w1"`
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For parallel processing (10 workers):
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`* * * * * seq 1 10 | xargs -P10 -I{} php /path/to/worker.php 10 "w{}"`
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See Settings → SMTP → Queue Worker Configuration for detailed commands.
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= Monitoring =
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Access statistics via:
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* **Newsletter → SMTP (by ROBOTSTXT)** - Queue status and recent campaigns
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* **Newsletter → Email Queue** - View all queued and sent emails
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* **Newsletter → Statistics** - Detailed campaign performance metrics
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= Recommended Settings =
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**For Standard SMTP Providers (SendGrid, Mailgun, etc.):**
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* Batch Size: 10-20
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* Max Per Connection: 50-100
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**For Amazon SES:**
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* Batch Size: 50
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**For Gmail/Outlook:**
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* Batch Size: 5
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* Max Per Connection: 20
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== Installation ==
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1. Install and activate Newsletter plugin
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2. Install and activate ROBOTSTXT SMTP plugin
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3. Configure SMTP settings in ROBOTSTXT SMTP
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4. Upload this plugin to `/wp-content/plugins/`
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5. Activate the plugin through the 'Plugins' menu
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6. Go to Newsletter → ROBOTSTXT SMTP to configure
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== Frequently Asked Questions ==
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= Do I need to configure SMTP settings? =
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No. The plugin uses the SMTP configuration from ROBOTSTXT SMTP plugin.
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= Does this work with Amazon SES? =
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Yes! If you have ROBOTSTXT SMTP Amazon SES plugin active, this plugin will automatically use SES API for even better performance.
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= Will this work with my current Newsletter campaigns? =
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Yes. This plugin seamlessly integrates with Newsletter's sending engine. Your existing campaigns will automatically benefit from improved performance.
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= What is SMTPKeepAlive? =
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SMTPKeepAlive is a PHPMailer feature that keeps the SMTP connection open between emails. Instead of connecting for each email, one connection is used for multiple emails, dramatically improving speed.
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= How much faster is this compared to default Newsletter sending? =
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In typical scenarios, you'll see 20-30x performance improvement. For example:
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* 10,000 emails: From 8-10 hours to 35 minutes
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* 50,000 emails: From 2 days to 3 hours
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= Does this respect rate limits? =
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Yes. The plugin integrates with ROBOTSTXT SMTP rate limiting system to ensure you don't exceed your provider's limits.
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== Changelog ==
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= 1.0.0 =
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* Initial release
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* SMTPKeepAlive support for SMTP
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* Amazon SES API integration
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* Batch processing
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* Settings page in Newsletter admin
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* Rate limiting integration
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== Upgrade Notice ==
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= 1.0.0 =
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Initial release of SMTP (by ROBOTSTXT) Newsletter.
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