diff --git a/server/utils/resend.js b/server/utils/resend.js
index 528ab94..6b69505 100644
--- a/server/utils/resend.js
+++ b/server/utils/resend.js
@@ -2,6 +2,17 @@ import { Resend } from "resend";
 
 const resend = new Resend(useRuntimeConfig().resendApiKey);
 
+// In dev/test runs (ALLOW_DEV_TEST_ENDPOINTS=true) skip live email dispatch so
+// local flows and e2e don't fire real Resend sends. Mirrors the gate in
+// server/api/admin/pre-registrants/invite.post.js.
+const skipEmailInDev = (label, to) => {
+  if (process.env.ALLOW_DEV_TEST_ENDPOINTS === "true") {
+    console.log(`[resend] DEV MODE — skipping ${label}`, { to });
+    return true;
+  }
+  return false;
+};
+
 const formatEventDate = (dateString, timeZone = "America/Toronto") => {
   const date = new Date(dateString);
   return new Intl.DateTimeFormat("en-US", {
@@ -58,6 +69,10 @@ Paid: $${registration.amountPaid.toFixed(2)} CAD`;
     ticketSection = "\nThis event is free for Ghost Guild members.\n";
   }
 
+  if (skipEmailInDev("registration email", registration.email)) {
+    return { success: true, skipped: true };
+  }
+
   try {
     const { data, error } = await resend.emails.send({
       from: "Ghost Guild <events@babyghosts.org>",
@@ -96,6 +111,10 @@ We look forward to seeing you there!`,
 export async function sendEventCancellationEmail(registration, eventData) {
   const baseUrl = process.env.BASE_URL || "https://ghostguild.org";
 
+  if (skipEmailInDev("cancellation email", registration.email)) {
+    return { success: true, skipped: true };
+  }
+
   try {
     const { data, error } = await resend.emails.send({
       from: "Ghost Guild <events@babyghosts.org>",
@@ -129,6 +148,10 @@ export async function sendWaitlistNotificationEmail(waitlistEntry, eventData) {
   const baseUrl = process.env.BASE_URL || "https://ghostguild.org";
   const eventUrl = `${baseUrl}/events/${eventData.slug || eventData._id}`;
 
+  if (skipEmailInDev("waitlist notification email", waitlistEntry.email)) {
+    return { success: true, skipped: true };
+  }
+
   try {
     const { data, error } = await resend.emails.send({
       from: "Ghost Guild <events@babyghosts.org>",
@@ -188,6 +211,10 @@ export async function sendSeriesPassConfirmation(options) {
     })
     .join("\n\n");
 
+  if (skipEmailInDev("series pass confirmation email", to)) {
+    return { success: true, skipped: true };
+  }
+
   try {
     const { data, error } = await resend.emails.send({
       from: "Ghost Guild <events@babyghosts.org>",
@@ -226,6 +253,10 @@ ${eventList}`,
 export async function sendWelcomeEmail(member) {
   const baseUrl = process.env.BASE_URL || "https://ghostguild.org";
 
+  if (skipEmailInDev("welcome email", member.email)) {
+    return { success: true, skipped: true };
+  }
+
   try {
     const { data, error } = await resend.emails.send({
       from: "Ghost Guild <ghostguild@babyghosts.org>",
@@ -238,6 +269,8 @@ Welcome to Ghost Guild! You're now part of the ${member.circle} circle.
 Sign in to your dashboard to get started:
 ${baseUrl}/member/dashboard
 
+Your Slack invitation arrives in our monthly onboarding waves — there may be a short wait.
+
 If you have questions, just reply to this email.`,
     });
 
diff --git a/tests/server/utils/resend.test.js b/tests/server/utils/resend.test.js
new file mode 100644
index 0000000..dbbbeb1
--- /dev/null
+++ b/tests/server/utils/resend.test.js
@@ -0,0 +1,85 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest'
+
+import {
+  sendEventRegistrationEmail,
+  sendEventCancellationEmail,
+  sendWaitlistNotificationEmail,
+  sendSeriesPassConfirmation,
+  sendWelcomeEmail,
+} from '../../../server/utils/resend.js'
+
+// Hoisted spy so the resend mock and the assertions share one reference.
+const { sendSpy } = vi.hoisted(() => ({ sendSpy: vi.fn() }))
+
+vi.mock('resend', () => ({
+  Resend: class {
+    constructor() {
+      this.emails = { send: sendSpy }
+    }
+  },
+}))
+
+const eventData = {
+  title: 'Co-op Basics',
+  startDate: '2026-06-01T17:00:00.000Z',
+  endDate: '2026-06-01T18:00:00.000Z',
+  location: 'Online',
+  slug: 'co-op-basics',
+}
+
+const registration = { email: 'reg@example.com', name: 'Reg', ticketType: 'member', amountPaid: 0 }
+
+const seriesPassOptions = {
+  to: 'pass@example.com',
+  name: 'Pass Holder',
+  series: { title: 'Workshop Series' },
+  ticket: { type: 'member', price: 0, currency: 'CAD', isFree: true },
+  events: [eventData],
+  paymentId: null,
+}
+
+const member = { email: 'welcome@example.com', name: 'New Member', circle: 'Community' }
+
+describe('resend email wrappers — ALLOW_DEV_TEST_ENDPOINTS gate', () => {
+  beforeEach(() => {
+    sendSpy.mockReset()
+    sendSpy.mockResolvedValue({ data: { id: 'email_1' }, error: null })
+  })
+  afterEach(() => {
+    delete process.env.ALLOW_DEV_TEST_ENDPOINTS
+  })
+
+  describe('when ALLOW_DEV_TEST_ENDPOINTS=true', () => {
+    beforeEach(() => {
+      process.env.ALLOW_DEV_TEST_ENDPOINTS = 'true'
+    })
+
+    const cases = [
+      ['registration', () => sendEventRegistrationEmail(registration, eventData)],
+      ['cancellation', () => sendEventCancellationEmail(registration, eventData)],
+      ['waitlist', () => sendWaitlistNotificationEmail(registration, eventData)],
+      ['series pass', () => sendSeriesPassConfirmation(seriesPassOptions)],
+      ['welcome', () => sendWelcomeEmail(member)],
+    ]
+
+    it.each(cases)('skips the live send for %s', async (_label, call) => {
+      const result = await call()
+      expect(result).toEqual({ success: true, skipped: true })
+      expect(sendSpy).not.toHaveBeenCalled()
+    })
+  })
+
+  describe('when the gate is off', () => {
+    it('dispatches a live send and returns success', async () => {
+      const result = await sendWelcomeEmail(member)
+      expect(sendSpy).toHaveBeenCalledTimes(1)
+      expect(result).toEqual({ success: true, data: { id: 'email_1' } })
+    })
+
+    it('includes the monthly-onboarding Slack-timing line in the welcome email', async () => {
+      await sendWelcomeEmail(member)
+      const sent = sendSpy.mock.calls[0][0]
+      expect(sent.text).toContain('monthly onboarding waves')
+    })
+  })
+})