What OMailer Does
OMailer replaces the default wp_mail() transport with a configurable SMTP stack, then layers a full email marketing suite on top. Version 3.3.1 ships 41 PHP modules covering every layer of email — from deliverability infrastructure to subscriber lifecycle management.
Module Groups
Core Infrastructure
- SMTP configuration with 5 presets (Gmail, Microsoft 365, Amazon SES, Zoho, Custom)
- Smart email routing with primary + failover connections
- Send queue with batch processing and rate limiting
- Email log with open/click/bounce tracking
- Alerts and delivery notifications
Marketing Suite
- Subscriber management with import/export and custom fields
- Tags, segments, and mailing lists
- Campaign builder with HTML and visual editors
- A/B split testing (subject, content, from-name)
- Automation sequences with 6 step types
- Double opt-in and subscribe forms (shortcode + Gutenberg block)
- Lead scoring engine (8 event types, configurable points)
- Subscriber lifecycle stages (Lead → Subscriber → Engaged → Customer → Advocate → Churned)
- Engagement scoring with daily decay and re-engagement triggers
Deliverability
- Bounce and complaint webhooks (Mailgun, SendGrid, Postmark)
- Spam score checker
- Suppression list (bounce, complaint, manual, import)
- IP warmup with 14-day schedule and bounce-rate guard
- Send time optimisation (per-subscriber optimal hour)
- SPF/DKIM/DMARC health checker
Integrations
- WooCommerce: checkout opt-in, abandoned cart, purchase automation, revenue attribution
- RSS-to-email digests with configurable check intervals
- Transactional email templates (10 WP + WooCommerce types)
- OForms native subscribe action
- REST API (namespace
omailer/v1) - Outbound webhooks (12 event types)
- WP-CLI commands
- White label mode
Plugin Constants
phpOM_VERSION // '3.3.1'
OM_PATH // Absolute path to plugin directory (trailing slash)
OM_URL // URL to plugin directory (trailing slash)
OM_BASENAME // 'omailer/omailer.php'
Requirements
- WordPress 6.0+
- PHP 8.0+
- MySQL 5.7+ / MariaDB 10.3+