diff --git a/server/trpc/index.ts b/server/trpc/index.ts
index 9a7d904ac..d4bea991e 100644
--- a/server/trpc/index.ts
+++ b/server/trpc/index.ts
@@ -4,6 +4,7 @@ import { revisionsRouter } from './revisions-router';
 import { scriptsRouter } from './scripts-router';
 import { waitlistRouter } from './waitlist-router';
 import { betaRouter } from './beta-router';
+import { mailRouter } from './mail-router';
 import type { TRPCContext } from './types';
 import type { TRPCError } from '@trpc/server';
 import { t } from './router';
@@ -15,6 +16,7 @@ export const appRouter = t.router({
   scripts: scriptsRouter,
   waitlist: waitlistRouter,
   beta: betaRouter,
+  mail: mailRouter,
 } as const);
 
 export type AppRouter = typeof appRouter;
diff --git a/server/trpc/mail-router.ts b/server/trpc/mail-router.ts
new file mode 100644
index 000000000..01ffaa3ed
--- /dev/null
+++ b/server/trpc/mail-router.ts
@@ -0,0 +1,155 @@
+import { z } from 'zod';
+import { baseRouter, publicProcedure, protectedProcedure } from './router';
+
+export const mailRouter = baseRouter({
+  messages: publicProcedure
+    .input(z.object({
+      folder: z.string().optional(),
+    }))
+    .query(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return [] as Array<{
+        id: string;
+        subject: string;
+        sender: { email: string; name?: string };
+        recipients: Array<{ email: string; name?: string }>;
+        body: string;
+        attachments?: Array<{
+          id: string;
+          filename: string;
+          mimeType: string;
+          size: number;
+          downloadUrl: string;
+        }>;
+        timestamp: string;
+        read: boolean;
+      }>;
+    }),
+
+  message: publicProcedure
+    .input(z.object({
+      messageId: z.string(),
+    }))
+    .query(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return {} as {
+        id: string;
+        subject: string;
+        sender: { email: string; name?: string };
+        recipients: Array<{ email: string; name?: string }>;
+        body: string;
+        attachments?: Array<{
+          id: string;
+          filename: string;
+          mimeType: string;
+          size: number;
+          downloadUrl: string;
+        }>;
+        timestamp: string;
+        read: boolean;
+      };
+    }),
+
+  send: protectedProcedure
+    .input(z.object({
+      to: z.array(z.string()),
+      subject: z.string(),
+      body: z.string(),
+      attachments: z.array(z.object({
+        id: z.string(),
+        filename: z.string(),
+        mimeType: z.string(),
+        size: z.number(),
+        downloadUrl: z.string(),
+      })).optional(),
+    }))
+    .mutation(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return {} as {
+        id: string;
+        subject: string;
+        sender: { email: string; name?: string };
+        recipients: Array<{ email: string; name?: string }>;
+        body: string;
+        attachments?: Array<{
+          id: string;
+          filename: string;
+          mimeType: string;
+          size: number;
+          downloadUrl: string;
+        }>;
+        timestamp: string;
+        read: boolean;
+      };
+    }),
+
+  contact: publicProcedure
+    .input(z.object({
+      email: z.string().email(),
+    }))
+    .query(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return null as {
+        id: string;
+        email: string;
+        name: string;
+        phone?: string;
+        organization?: string;
+      } | null;
+    }),
+
+  contacts: publicProcedure
+    .input(z.object({}))
+    .query(async ({ ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return [] as Array<{
+        id: string;
+        email: string;
+        name: string;
+        phone?: string;
+        organization?: string;
+      }>;
+    }),
+
+  addContact: protectedProcedure
+    .input(z.object({
+      email: z.string().email(),
+      name: z.string(),
+      phone: z.string().optional(),
+      organization: z.string().optional(),
+    }))
+    .mutation(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return {} as {
+        id: string;
+        email: string;
+        name: string;
+        phone?: string;
+        organization?: string;
+      };
+    }),
+
+  attachment: publicProcedure
+    .input(z.object({
+      attachmentId: z.string(),
+    }))
+    .query(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return {} as {
+        id: string;
+        filename: string;
+        mimeType: string;
+        size: number;
+        downloadUrl: string;
+      };
+    }),
+
+  attachmentDownload: publicProcedure
+    .input(z.object({
+      attachmentId: z.string(),
+    }))
+    .query(async ({ input, ctx }) => {
+      // TODO: Implement actual ProtonMail API call
+      return new Blob();
+    }),
+});
diff --git a/src/lib/mail/index.ts b/src/lib/mail/index.ts
new file mode 100644
index 000000000..b39ccd755
--- /dev/null
+++ b/src/lib/mail/index.ts
@@ -0,0 +1,2 @@
+export { ProtonMailClient, protonMail } from './protonmail-client';
+export type { ProtonMailMessage, ProtonMailAttachment, ProtonMailContact } from './protonmail-client';
diff --git a/src/lib/mail/protonmail-client.ts b/src/lib/mail/protonmail-client.ts
new file mode 100644
index 000000000..c06b5604d
--- /dev/null
+++ b/src/lib/mail/protonmail-client.ts
@@ -0,0 +1,84 @@
+import { trpc } from '../api/trpc-client';
+
+export interface ProtonMailMessage {
+  id: string;
+  subject: string;
+  sender: { email: string; name?: string };
+  recipients: Array<{ email: string; name?: string }>;
+  body: string;
+  attachments?: ProtonMailAttachment[];
+  timestamp: string;
+  read: boolean;
+}
+
+export interface ProtonMailAttachment {
+  id: string;
+  filename: string;
+  mimeType: string;
+  size: number;
+  downloadUrl: string;
+}
+
+export interface ProtonMailContact {
+  id: string;
+  email: string;
+  name: string;
+  phone?: string;
+  organization?: string;
+}
+
+export class ProtonMailClient {
+  constructor(private baseUrl: string = `${(import.meta as any).env?.VITE_API_URL || 'http://localhost:8080'}`) {}
+
+  async getMessages(folder?: string): Promise<ProtonMailMessage[]> {
+    const result = await trpc.mail.messages.query({ folder });
+    return result;
+  }
+
+  async getMessage(messageId: string): Promise<ProtonMailMessage> {
+    const result = await trpc.mail.message.query({ messageId });
+    return result;
+  }
+
+  async sendMessage(
+    to: string[],
+    subject: string,
+    body: string,
+    attachments?: ProtonMailAttachment[]
+  ): Promise<ProtonMailMessage> {
+    const result = await trpc.mail.send.mutate({
+      to,
+      subject,
+      body,
+      attachments,
+    });
+    return result;
+  }
+
+  async getContact(email: string): Promise<ProtonMailContact | null> {
+    const result = await trpc.mail.contact.query({ email });
+    return result;
+  }
+
+  async getContacts(): Promise<ProtonMailContact[]> {
+    const result = await trpc.mail.contacts.query({});
+    return result;
+  }
+
+  async addContact(contact: Omit<ProtonMailContact, 'id'>): Promise<ProtonMailContact> {
+    const result = await trpc.mail.addContact.mutate(contact);
+    return result;
+  }
+
+  async getAttachment(attachmentId: string): Promise<ProtonMailAttachment> {
+    const result = await trpc.mail.attachment.query({ attachmentId });
+    return result;
+  }
+
+  async downloadAttachment(attachmentId: string): Promise<Blob> {
+    const result = await trpc.mail.attachmentDownload.query({ attachmentId });
+    return result;
+  }
+}
+
+export const protonMail = new ProtonMailClient();