Omailer v3.3.2

What Omailer does

Replaces the default wp_mail() transport with a configurable SMTP stack, then layers a full email marketing suite on top.

Getting set up

Plugin constants

Defined in omailer.php at load time.

Database schema

All tables use the prefix {wpdb->prefix}om_. Use OM_DB::table( 'name' ) to get the full table name safely.

Settings reference

Stored in a single serialised array option: om_settings.

PHP$settings  = get_option( 'om_settings', [] );
$from_name = $settings['from_name'] ?? get_bloginfo('name');

Using shortcodes

[om_subscribe]
[om_subscribe title="Join our list" show_name="yes" list="2" tags="newsletter"]
[om_subscribe style="popup" trigger="exit"]
[om_subscribe style="slide-in" trigger="scroll" delay="50"]

We have [om_subscriber_count] subscribers.

Global helper functions

PHPom_send_email( string $to, string $subject, string $body, array $headers = [] ): bool

om_send_email(
    'user@example.com',
    'Your Order Confirmation',
    '<p>Thanks for your order!</p>',
    [ 'Reply-To: orders@mysite.com' ]
);

PHPom_subscribe( string $email, array $data = [] ): int|false
// $data: first_name, last_name, list_id, source, meta (field_key => value)

$sub_id = om_subscribe( 'jane@example.com', [
    'first_name' => 'Jane',
    'list_id'    => 3,
    'source'     => 'checkout',
    'meta'       => [ 'company' => 'Acme Corp' ],
] );

PHPom_unsubscribe( string $email ): bool

PHPom_add_tag( int $subscriber_id, string $tag_slug ): void
om_remove_tag( int $subscriber_id, string $tag_slug ): void

om_add_tag( 42, 'vip' );

Hooks & filters

PHPadd_action( 'om_subscriber_bounced', function( string $email, string $provider ) {
    error_log( "Bounce from {$provider} for {$email}" );
}, 10, 2 );

// Tag a WooCommerce customer on order completion
add_action( 'woocommerce_order_status_completed', function( int $order_id ) {
    $order = wc_get_order( $order_id );
    $sub   = OM_Subscriber::get_by_email( $order->get_billing_email() );
    if ( $sub ) om_add_tag( (int) $sub->id, 'customer' );
} );

PHPadd_filter( 'wp_mail', function( array $args ): array {
    $args['headers'][] = 'Bcc: archive@mycompany.com';
    return $args;
} );

AJAX endpoints

Managing subscribers

PHPOM_Subscriber::insert( array $data ): int|false
OM_Subscriber::get_by_email( string $email ): object|null
OM_Subscriber::get_by_id( int $id ): object|null
OM_Subscriber::update( int $id, array $data ): void
OM_Subscriber::count( string $status = 'subscribed' ): int
OM_Subscriber::get_all( array $args ): array   // args: search, status, list_id, per_page, page
OM_Subscriber::add_to_list( int $subscriber_id, int $list_id ): void

email,first_name,last_name,status
john@example.com,John,Doe,subscribed
jane@example.com,Jane,,subscribed

Tags & segmentation

PHPOM_Tags::get_all(): array                              // includes subscriber_count
OM_Tags::create( string $name ): int|false            // slug auto-generated
OM_Tags::delete( int $tag_id ): void                  // removes all assignments
OM_Tags::add_to_subscriber( int $sub_id, int $tag_id ): void
// fires: do_action( 'om_tag_added', $subscriber_id, $tag_id )
OM_Tags::remove_from_subscriber( int $sub_id, int $tag_id ): void
OM_Tags::get_for_subscriber( int $sub_id ): array
OM_Tags::add_by_slug( int $sub_id, string $slug ): void  // creates tag if needed

Custom fields & merge tags

PHP$html         = '<p>Hi {{first_name}},</p><p>Your company: {{company}}</p>';
$subscriber   = OM_Subscriber::get_by_email( 'jane@example.com' );
$personalised = OM_Custom_Fields::apply_merge_tags( $html, $subscriber );

Mailing lists

Subscribers can belong to one or more named lists. The "General" list is created on activation and cannot be deleted.

PHPOM_Subscriber::create_list( string $name, string $description = '' ): int
OM_Subscriber::delete_list( int $list_id ): void         // subscribers NOT deleted
OM_Subscriber::add_to_list( int $subscriber_id, int $list_id ): void
OM_Subscriber::remove_from_list( int $subscriber_id, int $list_id ): void

Building campaigns

PHPOM_Campaign::get_all(): array
OM_Campaign::get_by_id( int $id ): object|null
OM_Campaign::save( array $data ): int|false
OM_Campaign::delete( int $id ): void
OM_Campaign::duplicate( int $id ): int|false    // creates a draft copy

// Dispatch immediately
OM_Sender::dispatch( int $campaign_id ): void

The cron event om_send_scheduled fires hourly and processes campaigns with status = 'scheduled' and scheduled_at <= NOW(). All merge tags are replaced per subscriber at send time.

Automation sequences

PHPadd_action( 'user_purchase', function( int $subscriber_id ) {
    OM_Automation::trigger( 'wp_hook', $subscriber_id, 'user_purchase' );
} );

// Cron: om_process_automations every 5 minutes, processes up to 100 active runs

Double opt-in

When double_optin is enabled, new subscribers are created with status = 'pending' and a random token. A confirmation email links to:

/?om_action=confirm&token={confirmation_token}

On visit: status → subscribed, token cleared, confirmed_at set, OM_Automation::trigger( 'subscribe', ... ) fires.

Bounce & complaint webhooks

Register these URLs with your email provider. Supported: mailgun, sendgrid, postmark.

https://yoursite.com/omailer/webhook/{provider}/

Spam score checker

PHP$result = OM_Spam_Score::analyse( string $subject, string $body ): array;
// Returns: [ 'score' => 12, 'grade' => 'B', 'issues' => [ [...], ... ] ]

Deliverability tools

PHP$results = OM_Deliverability::check_domain( 'yourdomain.com' );
// Returns: [ 'domain', 'checked', 'score' => 85,
//            'spf' => [...], 'dkim' => [...], 'dmarc' => [...] ]

PHP$window = OM_Deliverability::get_best_send_window( int $days = 30 ): array;
// Returns: [ 'suggestion' => '...', 'top_windows' => [ ['day','hour','label','opens'], ... ] ]

Email builder

JSOmBuilder.init( 'my-container-id' );
const html = OmBuilder.exportHTML();
OmBuilder.setBlocks( OmBuilder.getBlocks() );

window.omBuilderExport = function( html ) {
    document.getElementById('om_html_content').value = html;
};

Gutenberg block

Block name: omailer/subscribe-form, registered in assets/js/om-gutenberg.js. Dynamic block: save() returns null, output rendered server-side.

Public subscribe forms

assets/js/om-public.js is enqueued on all front-end pages. Handles fetch-based inline submissions, overlay lifecycle, custom field serialisation, and auto-close after subscribe.

SMTP configuration

Connections are stored in om_smtp_connections as an associative array keyed by UUID.

PHPOM_SMTP::get_connections(): array
OM_SMTP::get_connection( string $id ): array|null
OM_SMTP::get_primary_id(): string|null
OM_SMTP::get_backup_id(): string|null
OM_SMTP::get_presets(): array

Built-in presets: Gmail, Microsoft 365, Amazon SES, Zoho, Custom SMTP. (Bounce / complaint webhook ingestion is supported separately for Mailgun, SendGrid, and Postmark; see Bounce Tracking.)

On primary connection failure, Omailer retries with the backup connection. If both fail, falls back to PHP's mail().

Smart email routing

OM_Smart_Routing routes outbound emails to specific SMTP connections based on recipient domain, email type, or source plugin. Rules evaluate top-to-bottom; first match wins.

• Recipient domain: send all @bigcorp.com emails via a dedicated connection
• Email type: transactional, notification, or marketing
• Source plugin: e.g. woocommerce, contact-form-7

Email log

All outbound emails are logged: subject, recipient, status, source plugin, timestamps. Body content is optional via om_log_settings['log_body'].

PHPOM_Email_Log::get_logs( array $args ): array      // args: search, status, per_page, page
OM_Email_Log::get_status_counts(): array
OM_Email_Log::resend( int $log_id ): bool
OM_Email_Log::export( string $format ): void       // 'csv' or 'json', streams download

Logs are purged after 90 days (configurable via om_log_retention_days).

Failure alerts

Sends an admin email when an outbound email fails. Settings in om_alert_settings:

Email controls

Toggle WordPress core email notifications on/off without code: new user registration, password reset, auto-updates, comment notifications, and more.

PHPOM_Email_Controls::get_controls_list(): array
OM_Email_Controls::get_settings(): array

Performance & queue

When async mode is enabled, all wp_mail() calls are stored in om_email_queue and dispatched in the background by cron.

Misc settings

JavaScript APIs

JSOM.ajax_url        // admin-ajax.php URL
OM.nonce           // om_admin nonce
OM.export_url      // CSV export URL
OM.log_export_csv  // Log CSV export URL
OM.log_export_json // Log JSON export URL

What's changed