How sibling plugins register notification types via mam_notification_list. Each type declares its slug, replacement tokens, default-on channels, and description. The dispatcher resolves the message_type to one of these entries.

How each of the three notification channels is sent: wp_mail or queue for email, the global $sms object for SMS, and APNs/FCM via MAM_PushDispatcher for push. Covers the per-channel sender…

How email, SMS, and push notifications are queued and drained by the mail-cron-manager subsystem. Covers the wp_mam_mail_queue and wp_mam_pn_text_queue tables, the per-tick batch sizes (50 email / 20 PN+SMS), and…

How wp_mam_notifications_history records every dispatch, how the in-app notification center reads it, and the opt-out tables (per-user email opt-out, SMS STOP, push permission revocation).

How replacement tokens (e.g., [user_login], [passwordcode], [order_id]) work in notification templates: per-type token list declared in mam_notification_list, supplied at fire time, substituted by the channel sender.