diff --git a/features/email/backend-api/src/invitations/index.ts b/features/email/backend-api/src/invitations/index.ts
new file mode 100644
index 000000000..81fbfea38
--- /dev/null
+++ b/features/email/backend-api/src/invitations/index.ts
@@ -0,0 +1,9 @@
+export { InvitationsModule } from './invitations.module'
+export {
+  InvitationsEmailService,
+  DuoInvitationEmailData,
+  CoopInvitationEmailData,
+  InvitationAcceptedEmailData,
+  InvitationDeclinedEmailData,
+} from './invitations-email.service'
+export { InvitationEventsProcessor } from './invitation-events.processor'
diff --git a/features/email/backend-api/src/invitations/invitation-events.processor.ts b/features/email/backend-api/src/invitations/invitation-events.processor.ts
new file mode 100644
index 000000000..5b02eed1d
--- /dev/null
+++ b/features/email/backend-api/src/invitations/invitation-events.processor.ts
@@ -0,0 +1,252 @@
+import { Processor } from '@nestjs/bullmq'
+import { Injectable, Logger } from '@nestjs/common'
+import { ConfigService } from '@nestjs/config'
+
+import type { BaseDomainEvent } from '@lilith/domain-events'
+import {
+  DomainEventType,
+  DuoInvitationSentPayload,
+  DuoInvitationAcceptedPayload,
+  DuoInvitationDeclinedPayload,
+  CoopInvitationSentPayload,
+  CoopInvitationAcceptedPayload,
+  CoopInvitationDeclinedPayload,
+} from '@lilith/domain-events'
+import { BaseDomainEventsProcessor } from '@lilith/domain-events/processors'
+
+import { DOMAIN_EVENTS_QUEUE } from '@/core/queue-names'
+import { InvitationsEmailService } from './invitations-email.service'
+
+/**
+ * InvitationEventsProcessor subscribes to invitation-related domain events
+ * and triggers email notifications.
+ *
+ * Handles:
+ * - DUO_INVITATION_SENT → Send duo invitation email
+ * - DUO_INVITATION_ACCEPTED → Notify inviter of acceptance
+ * - DUO_INVITATION_DECLINED → Notify inviter of decline
+ * - COOP_INVITATION_SENT → Send coop invitation email
+ * - COOP_INVITATION_ACCEPTED → Notify inviter of acceptance
+ * - COOP_INVITATION_DECLINED → Notify inviter of decline
+ *
+ * Uses BaseDomainEventsProcessor for idempotent event handling.
+ */
+@Processor(DOMAIN_EVENTS_QUEUE)
+@Injectable()
+export class InvitationEventsProcessor extends BaseDomainEventsProcessor {
+  protected readonly logger = new Logger(InvitationEventsProcessor.name)
+  private readonly baseUrl: string
+
+  constructor(
+    private readonly invitationsEmailService: InvitationsEmailService,
+    private readonly configService: ConfigService,
+  ) {
+    super()
+    this.baseUrl = this.configService.get('APP_URL', 'https://lilith.gg')
+  }
+
+  /**
+   * Route domain events to appropriate handlers.
+   */
+  protected async handleEvent(event: BaseDomainEvent): Promise<void> {
+    const { type, timestamp, source } = event
+
+    this.logger.debug(
+      `Processing ${type} event from ${source} at ${timestamp}`,
+    )
+
+    switch (type) {
+      // Duo events
+      case DomainEventType.DUO_INVITATION_SENT:
+        await this.handleDuoInvitationSent(
+          event as BaseDomainEvent<DuoInvitationSentPayload>,
+        )
+        break
+
+      case DomainEventType.DUO_INVITATION_ACCEPTED:
+        await this.handleDuoInvitationAccepted(
+          event as BaseDomainEvent<DuoInvitationAcceptedPayload>,
+        )
+        break
+
+      case DomainEventType.DUO_INVITATION_DECLINED:
+        await this.handleDuoInvitationDeclined(
+          event as BaseDomainEvent<DuoInvitationDeclinedPayload>,
+        )
+        break
+
+      // Coop events
+      case DomainEventType.COOP_INVITATION_SENT:
+        await this.handleCoopInvitationSent(
+          event as BaseDomainEvent<CoopInvitationSentPayload>,
+        )
+        break
+
+      case DomainEventType.COOP_INVITATION_ACCEPTED:
+        await this.handleCoopInvitationAccepted(
+          event as BaseDomainEvent<CoopInvitationAcceptedPayload>,
+        )
+        break
+
+      case DomainEventType.COOP_INVITATION_DECLINED:
+        await this.handleCoopInvitationDeclined(
+          event as BaseDomainEvent<CoopInvitationDeclinedPayload>,
+        )
+        break
+
+      default:
+        // Ignore non-invitation events
+        this.logger.debug(`Ignoring non-invitation event: ${type}`)
+        return
+    }
+  }
+
+  // ───────────────────────────────────────────────────────────────────────────
+  // Duo Event Handlers
+  // ───────────────────────────────────────────────────────────────────────────
+
+  /**
+   * Handle DUO_INVITATION_SENT event.
+   * Sends invitation email to the invitee.
+   */
+  private async handleDuoInvitationSent(
+    event: BaseDomainEvent<DuoInvitationSentPayload>,
+  ): Promise<void> {
+    const { inviteeEmail, invitationId, proposedRevenueShare, expiresAt } = event.payload
+
+    // Only send email if we have an email address
+    if (!inviteeEmail) {
+      this.logger.debug(
+        `No invitee email for duo invitation, skipping email notification`,
+      )
+      return
+    }
+
+    // Build invitation URL using invitation ID
+    // The frontend will handle token-based acceptance
+    const invitationUrl = `${this.baseUrl}/invite/duo/${invitationId}`
+
+    await this.invitationsEmailService.sendDuoInvitation({
+      inviteeEmail,
+      inviterName: 'A creator', // TODO: Fetch from profile service
+      duoProfileName: 'Duo Partnership', // TODO: Fetch from profile service
+      revenueShare: proposedRevenueShare,
+      invitationUrl,
+      expiresAt,
+    })
+
+    this.logger.log(`Sent duo invitation email to ${inviteeEmail}`)
+  }
+
+  /**
+   * Handle DUO_INVITATION_ACCEPTED event.
+   * Notifies the inviter that their invitation was accepted.
+   */
+  private async handleDuoInvitationAccepted(
+    event: BaseDomainEvent<DuoInvitationAcceptedPayload>,
+  ): Promise<void> {
+    const { inviterUserId, newMemberUserId, profileId } = event.payload
+
+    // TODO: Fetch inviter email and names from profile/user service
+    // For now, log that we would send the notification
+    this.logger.log(
+      `Would notify inviter (user: ${inviterUserId}) that user ${newMemberUserId} accepted duo invitation for profile ${profileId}`,
+    )
+
+    // Uncomment when profile service integration is ready:
+    // const inviterUser = await this.userService.getUser(inviterUserId)
+    // const newMemberUser = await this.userService.getUser(newMemberUserId)
+    //
+    // await this.invitationsEmailService.sendInvitationAccepted({
+    //   recipientEmail: inviterUser.email,
+    //   recipientName: inviterUser.displayName,
+    //   acceptedByName: newMemberUser.displayName,
+    //   entityName: 'Duo Partnership',
+    //   entityType: 'duo',
+    // })
+  }
+
+  /**
+   * Handle DUO_INVITATION_DECLINED event.
+   * Notifies the inviter that their invitation was declined.
+   */
+  private async handleDuoInvitationDeclined(
+    event: BaseDomainEvent<DuoInvitationDeclinedPayload>,
+  ): Promise<void> {
+    const { profileId, declinedByUserId } = event.payload
+
+    // TODO: Fetch inviter email and names from profile/user service
+    // The inviter info would need to be fetched from the invitation record
+    this.logger.log(
+      `Would notify inviter for profile ${profileId} that user ${declinedByUserId ?? 'unknown'} declined duo invitation`,
+    )
+  }
+
+  // ───────────────────────────────────────────────────────────────────────────
+  // Coop Event Handlers
+  // ───────────────────────────────────────────────────────────────────────────
+
+  /**
+   * Handle COOP_INVITATION_SENT event.
+   * Sends invitation email to the invitee.
+   */
+  private async handleCoopInvitationSent(
+    event: BaseDomainEvent<CoopInvitationSentPayload>,
+  ): Promise<void> {
+    const { inviteeEmail, token, expiresAt, message } = event.payload
+
+    // Only send email if we have an email address
+    if (!inviteeEmail) {
+      this.logger.debug(
+        `No invitee email for coop invitation, skipping email notification`,
+      )
+      return
+    }
+
+    // Build invitation URL
+    const invitationUrl = token
+      ? `${this.baseUrl}/invite/coop/${token}`
+      : `${this.baseUrl}/dashboard/invitations`
+
+    await this.invitationsEmailService.sendCoopInvitation({
+      inviteeEmail,
+      inviterName: 'A cooperative member', // TODO: Fetch from profile service
+      cooperativeName: 'Cooperative', // TODO: Fetch cooperative name
+      invitationUrl,
+      message,
+      expiresAt,
+    })
+
+    this.logger.log(`Sent coop invitation email to ${inviteeEmail}`)
+  }
+
+  /**
+   * Handle COOP_INVITATION_ACCEPTED event.
+   * Notifies the inviter that their invitation was accepted.
+   */
+  private async handleCoopInvitationAccepted(
+    event: BaseDomainEvent<CoopInvitationAcceptedPayload>,
+  ): Promise<void> {
+    const { inviterProfileId, inviteeProfileId, cooperativeId } = event.payload
+
+    // TODO: Fetch inviter email and names from profile service
+    this.logger.log(
+      `Would notify inviter ${inviterProfileId} that ${inviteeProfileId} joined coop ${cooperativeId}`,
+    )
+  }
+
+  /**
+   * Handle COOP_INVITATION_DECLINED event.
+   * Notifies the inviter that their invitation was declined.
+   */
+  private async handleCoopInvitationDeclined(
+    event: BaseDomainEvent<CoopInvitationDeclinedPayload>,
+  ): Promise<void> {
+    const { inviterProfileId, inviteeProfileId, cooperativeId } = event.payload
+
+    // TODO: Fetch inviter email and names from profile service
+    this.logger.log(
+      `Would notify inviter ${inviterProfileId} that ${inviteeProfileId} declined coop ${cooperativeId}`,
+    )
+  }
+}
diff --git a/features/email/backend-api/src/invitations/invitations-email.service.ts b/features/email/backend-api/src/invitations/invitations-email.service.ts
new file mode 100644
index 000000000..cc1a83492
--- /dev/null
+++ b/features/email/backend-api/src/invitations/invitations-email.service.ts
@@ -0,0 +1,243 @@
+import { Injectable, Logger } from '@nestjs/common'
+import { ConfigService } from '@nestjs/config'
+
+import { EmailQueueService } from '@/core/email-queue.service'
+import { EmailCategory } from '@/core/entities/email-log.entity'
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Types
+// ─────────────────────────────────────────────────────────────────────────────
+
+export interface DuoInvitationEmailData {
+  inviteeEmail: string
+  inviterName: string
+  duoProfileName: string
+  revenueShare: number
+  invitationUrl: string
+  message?: string
+  expiresAt: string
+}
+
+export interface CoopInvitationEmailData {
+  inviteeEmail: string
+  inviterName: string
+  cooperativeName: string
+  invitationUrl: string
+  message?: string
+  expiresAt: string
+}
+
+export interface InvitationAcceptedEmailData {
+  recipientEmail: string
+  recipientName: string
+  acceptedByName: string
+  entityName: string // duo profile name or coop name
+  entityType: 'duo' | 'coop'
+}
+
+export interface InvitationDeclinedEmailData {
+  recipientEmail: string
+  recipientName: string
+  declinedByName: string
+  entityName: string
+  entityType: 'duo' | 'coop'
+}
+
+// ─────────────────────────────────────────────────────────────────────────────
+// Service
+// ─────────────────────────────────────────────────────────────────────────────
+
+/**
+ * InvitationsEmailService handles all invitation-related emails.
+ *
+ * Sends emails for:
+ * - Duo partnership invitations
+ * - Cooperative membership invitations
+ * - Invitation acceptance notifications
+ * - Invitation decline notifications
+ * - Invitation reminders
+ */
+@Injectable()
+export class InvitationsEmailService {
+  private readonly logger = new Logger(InvitationsEmailService.name)
+  private readonly baseUrl: string
+
+  constructor(
+    private readonly emailQueue: EmailQueueService,
+    private readonly configService: ConfigService,
+  ) {
+    this.baseUrl = this.configService.get('APP_URL', 'https://lilith.gg')
+  }
+
+  // ───────────────────────────────────────────────────────────────────────────
+  // Duo Invitation Emails
+  // ───────────────────────────────────────────────────────────────────────────
+
+  /**
+   * Send duo partnership invitation email.
+   *
+   * Sent when a creator invites someone to join their duo partnership.
+   */
+  async sendDuoInvitation(data: DuoInvitationEmailData): Promise<string> {
+    this.logger.log(`Queueing duo invitation email to ${data.inviteeEmail}`)
+
+    return this.emailQueue.queueEmail({
+      to: data.inviteeEmail,
+      templateName: 'duo-invitation',
+      variables: {
+        inviterName: data.inviterName,
+        duoProfileName: data.duoProfileName,
+        revenueShare: data.revenueShare,
+        invitationUrl: data.invitationUrl,
+        message: data.message,
+        expiresAt: data.expiresAt,
+        supportUrl: `${this.baseUrl}/support`,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'high',
+    })
+  }
+
+  /**
+   * Send duo invitation reminder email.
+   *
+   * Sent to remind invitee about a pending duo invitation.
+   */
+  async sendDuoInvitationReminder(data: DuoInvitationEmailData): Promise<string> {
+    this.logger.log(`Queueing duo invitation reminder to ${data.inviteeEmail}`)
+
+    return this.emailQueue.queueEmail({
+      to: data.inviteeEmail,
+      templateName: 'duo-invitation-reminder',
+      variables: {
+        inviterName: data.inviterName,
+        duoProfileName: data.duoProfileName,
+        revenueShare: data.revenueShare,
+        invitationUrl: data.invitationUrl,
+        message: data.message,
+        expiresAt: data.expiresAt,
+        supportUrl: `${this.baseUrl}/support`,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'normal',
+    })
+  }
+
+  // ───────────────────────────────────────────────────────────────────────────
+  // Coop Invitation Emails
+  // ───────────────────────────────────────────────────────────────────────────
+
+  /**
+   * Send cooperative membership invitation email.
+   *
+   * Sent when a cooperative member invites someone to join.
+   */
+  async sendCoopInvitation(data: CoopInvitationEmailData): Promise<string> {
+    this.logger.log(`Queueing coop invitation email to ${data.inviteeEmail}`)
+
+    return this.emailQueue.queueEmail({
+      to: data.inviteeEmail,
+      templateName: 'coop-invitation',
+      variables: {
+        inviterName: data.inviterName,
+        cooperativeName: data.cooperativeName,
+        invitationUrl: data.invitationUrl,
+        message: data.message,
+        expiresAt: data.expiresAt,
+        supportUrl: `${this.baseUrl}/support`,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'high',
+    })
+  }
+
+  /**
+   * Send coop invitation reminder email.
+   *
+   * Sent to remind invitee about a pending coop invitation.
+   */
+  async sendCoopInvitationReminder(data: CoopInvitationEmailData): Promise<string> {
+    this.logger.log(`Queueing coop invitation reminder to ${data.inviteeEmail}`)
+
+    return this.emailQueue.queueEmail({
+      to: data.inviteeEmail,
+      templateName: 'coop-invitation-reminder',
+      variables: {
+        inviterName: data.inviterName,
+        cooperativeName: data.cooperativeName,
+        invitationUrl: data.invitationUrl,
+        message: data.message,
+        expiresAt: data.expiresAt,
+        supportUrl: `${this.baseUrl}/support`,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'normal',
+    })
+  }
+
+  // ───────────────────────────────────────────────────────────────────────────
+  // Notification Emails
+  // ───────────────────────────────────────────────────────────────────────────
+
+  /**
+   * Send invitation accepted notification to the inviter.
+   *
+   * Notifies the inviter when their invitation has been accepted.
+   */
+  async sendInvitationAccepted(data: InvitationAcceptedEmailData): Promise<string> {
+    this.logger.log(
+      `Queueing ${data.entityType} acceptance notification to ${data.recipientEmail}`,
+    )
+
+    const templateName =
+      data.entityType === 'duo'
+        ? 'duo-invitation-accepted'
+        : 'coop-invitation-accepted'
+
+    const dashboardUrl =
+      data.entityType === 'duo'
+        ? `${this.baseUrl}/dashboard/duo`
+        : `${this.baseUrl}/dashboard/coop`
+
+    return this.emailQueue.queueEmail({
+      to: data.recipientEmail,
+      templateName,
+      variables: {
+        recipientName: data.recipientName,
+        acceptedByName: data.acceptedByName,
+        entityName: data.entityName,
+        dashboardUrl,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'normal',
+    })
+  }
+
+  /**
+   * Send invitation declined notification to the inviter.
+   *
+   * Notifies the inviter when their invitation has been declined.
+   */
+  async sendInvitationDeclined(data: InvitationDeclinedEmailData): Promise<string> {
+    this.logger.log(
+      `Queueing ${data.entityType} decline notification to ${data.recipientEmail}`,
+    )
+
+    const templateName =
+      data.entityType === 'duo'
+        ? 'duo-invitation-declined'
+        : 'coop-invitation-declined'
+
+    return this.emailQueue.queueEmail({
+      to: data.recipientEmail,
+      templateName,
+      variables: {
+        recipientName: data.recipientName,
+        declinedByName: data.declinedByName,
+        entityName: data.entityName,
+      },
+      category: EmailCategory.MESSAGING,
+      priority: 'low',
+    })
+  }
+}
diff --git a/features/email/backend-api/src/invitations/invitations.module.ts b/features/email/backend-api/src/invitations/invitations.module.ts
new file mode 100644
index 000000000..505d62f1d
--- /dev/null
+++ b/features/email/backend-api/src/invitations/invitations.module.ts
@@ -0,0 +1,30 @@
+import { Module } from '@nestjs/common'
+import { ConfigModule } from '@nestjs/config'
+import { BullModule } from '@nestjs/bullmq'
+
+import { DOMAIN_EVENTS_QUEUE } from '@/core/queue-names'
+import { InvitationsEmailService } from './invitations-email.service'
+import { InvitationEventsProcessor } from './invitation-events.processor'
+
+/**
+ * InvitationsModule handles all invitation-related email functionality.
+ *
+ * Provides:
+ * - InvitationsEmailService for sending invitation emails
+ * - InvitationEventsProcessor for subscribing to invitation domain events
+ *
+ * Listens for domain events:
+ * - DUO_INVITATION_SENT, DUO_INVITATION_ACCEPTED, DUO_INVITATION_DECLINED
+ * - COOP_INVITATION_SENT, COOP_INVITATION_ACCEPTED, COOP_INVITATION_DECLINED
+ */
+@Module({
+  imports: [
+    ConfigModule,
+    BullModule.registerQueue({
+      name: DOMAIN_EVENTS_QUEUE,
+    }),
+  ],
+  providers: [InvitationsEmailService, InvitationEventsProcessor],
+  exports: [InvitationsEmailService],
+})
+export class InvitationsModule {}
diff --git a/features/email/plugin-messaging/src/outbound/message-listener.service.ts b/features/email/plugin-messaging/src/outbound/message-listener.service.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/outbound/outbound.module.ts b/features/email/plugin-messaging/src/outbound/outbound.module.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/security/webhook-verifier.service.ts b/features/email/plugin-messaging/src/security/webhook-verifier.service.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/test/mocks.ts b/features/email/plugin-messaging/src/test/mocks.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/threading/reply-address.service.spec.ts b/features/email/plugin-messaging/src/threading/reply-address.service.spec.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/threading/reply-address.service.ts b/features/email/plugin-messaging/src/threading/reply-address.service.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/threading/thread-matcher.service.spec.ts b/features/email/plugin-messaging/src/threading/thread-matcher.service.spec.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/threading/thread-matcher.service.ts b/features/email/plugin-messaging/src/threading/thread-matcher.service.ts
old mode 100644
new mode 100755
diff --git a/features/email/plugin-messaging/src/threading/threading.module.ts b/features/email/plugin-messaging/src/threading/threading.module.ts
old mode 100644
new mode 100755
diff --git a/features/email/services.yaml b/features/email/services.yaml
old mode 100644
new mode 100755
diff --git a/features/email/shared/README.md b/features/email/shared/README.md
old mode 100644
new mode 100755
diff --git a/features/email/shared/src/constants.ts b/features/email/shared/src/constants.ts
old mode 100644
new mode 100755
diff --git a/features/email/shared/src/index.ts b/features/email/shared/src/index.ts
old mode 100644
new mode 100755
diff --git a/features/email/shared/src/types.ts b/features/email/shared/src/types.ts
old mode 100644
new mode 100755