graph TB
    subgraph "Email Infrastructure"
        SMTP[SMTP Pool]
        IP[IP Pool]
        DOMAIN[Domain Auth]
        PROVIDER[Providers]
    end

    subgraph "Email Management"
        TEMPLATE[Templates]
        CAMPAIGN[Campaigns]
        TRANSACT[Transactional]
    end

    subgraph "Automation"
        RULES[Automation Rules]
        TRIGGERS[Triggers]
        SEQUENCE[Sequences]
    end

    subgraph "Delivery"
        SEND[Sending]
        TRACK[Tracking]
        ANALYTICS[Analytics]
    end

    TEMPLATE --> CAMPAIGN
    TEMPLATE --> TRANSACT
    CAMPAIGN --> RULES
    RULES --> TRIGGERS
    TRIGGERS --> SEQUENCE
    SEQUENCE --> SEND
    SEND --> TRACK
    TRACK --> ANALYTICS

    SMTP --> SEND
    IP --> SMTP
    DOMAIN --> PROVIDER
    PROVIDER --> SMTP

    style SMTP fill:#e1f5fe
    style SEND fill:#fff3e0
    style TRACK fill:#e8f5e9

erDiagram
    TENANT ||--o{ EMAIL_TEMPLATE : has
    TENANT ||--o{ EMAIL_CAMPAIGN : has
    TENANT ||--o{ EMAIL_AUTOMATION_RULE : has

    EMAIL_CAMPAIGN ||--o{ EMAIL : sends
    EMAIL_TEMPLATE ||--o{ EMAIL : uses

    EMAIL ||--o{ EMAIL_EVENT : logs
    EMAIL }o--|| CONTACT : sent_to

    EMAIL_AUTOMATION_RULE ||--o{ AUTOMATION_ACTION : triggers

    EMAIL {
        string id PK
        string tenantId FK
        string templateId FK
        string contactId FK
        string subject
        string fromEmail
        string toEmail
        enum status
        timestamp sentAt
        timestamp openedAt
        timestamp clickedAt
        string messageId
    }

    EMAIL_TEMPLATE {
        string id PK
        string tenantId FK
        string name
        string subject
        text htmlContent
        text textContent
        json variables
        enum type
        boolean active
    }

    EMAIL_CAMPAIGN {
        string id PK
        string tenantId FK
        string name
        string templateId FK
        json segmentCriteria
        enum status
        timestamp scheduledAt
        timestamp sentAt
        int totalSent
        int totalOpened
    }

    EMAIL_AUTOMATION_RULE {
        string id PK
        string tenantId FK
        string name
        enum triggerType
        json conditions
        json actions
        boolean active
        int priority
    }

    EMAIL_EVENT {
        string id PK
        string emailId FK
        enum eventType
        json eventData
        string ipAddress
        string userAgent
        timestamp occurredAt
    }

stateDiagram-v2
    [*] --> QUEUED: Create Email

    QUEUED --> SENDING: Pick from Queue
    SENDING --> SENT: Successfully Sent
    SENDING --> FAILED: Send Error

    SENT --> DELIVERED: Delivery Confirmed
    SENT --> BOUNCED: Bounce Received

    DELIVERED --> OPENED: Open Tracked
    DELIVERED --> UNSUBSCRIBED: Unsubscribe Click

    OPENED --> CLICKED: Link Click
    OPENED --> SPAM_REPORTED: Spam Report

    BOUNCED --> SUPPRESSED: Add to Suppression

    FAILED --> QUEUED: Retry
    FAILED --> SUPPRESSED: Max Retries

    note right of BOUNCED
        Hard or soft bounce
    end note

flowchart TB
    subgraph "Application Layer"
        APP[Company Manager]
        QUEUE[Email Queue]
    end

    subgraph "Sending Infrastructure"
        WORKER[Email Workers]
        RATE[Rate Limiter]
        POOL[IP Pool Manager]
    end

    subgraph "Providers"
        SES[Amazon SES]
        SMTP_PROV[SMTP Provider]
        RESEND[Resend]
    end

    subgraph "Feedback"
        WEBHOOK[Webhook Handler]
        BOUNCE[Bounce Handler]
        COMPLAINT[Complaint Handler]
    end

    APP --> QUEUE
    QUEUE --> WORKER
    WORKER --> RATE
    RATE --> POOL
    POOL --> SES
    POOL --> SMTP_PROV
    POOL --> RESEND

    SES --> WEBHOOK
    SMTP_PROV --> WEBHOOK
    WEBHOOK --> BOUNCE
    WEBHOOK --> COMPLAINT

    BOUNCE --> APP
    COMPLAINT --> APP