diff --git a/src/models/messages.ts b/src/models/messages.ts
index f09fe7d4..455d042c 100644
--- a/src/models/messages.ts
+++ b/src/models/messages.ts
@@ -356,3 +356,28 @@ export interface CleanMessagesResponse extends Message {
    */
   conversation: string;
 }
+
+/**
+ * Interface representing a request to send a message using raw MIME format.
+ */
+export interface SendMimeMessageRequest {
+  /**
+   * The raw MIME content of the message to send.
+   */
+  mime: string;
+  /**
+   * Optional metadata to attach to the message.
+   * Defaults to empty string if not provided.
+   */
+  metadata?: string;
+}
+
+/**
+ * Interface representing the query parameters for sending a MIME message.
+ */
+export interface SendMimeMessageQueryParams {
+  /**
+   * The type of message being sent. Must be 'mime' for MIME messages.
+   */
+  type: 'mime';
+}
diff --git a/src/resources/messages.ts b/src/resources/messages.ts
index 33693972..279b62b2 100644
--- a/src/resources/messages.ts
+++ b/src/resources/messages.ts
@@ -14,6 +14,8 @@ import {
   Message,
   ScheduledMessage,
   ScheduledMessagesList,
+  SendMimeMessageRequest,
+  SendMimeMessageQueryParams,
   StopScheduledMessageResponse,
   UpdateMessageRequest,
 } from '../models/messages.js';
@@ -85,6 +87,18 @@ export interface SendMessageParams {
   requestBody: SendMessageRequest;
 }
 
+/**
+ * The parameters for the {@link Messages.sendMime} method
+ * @property identifier The identifier of the grant to act upon
+ * @property requestBody The MIME message to send
+ * @property queryParams The query parameters for the MIME send request
+ */
+export interface SendMimeMessageParams {
+  identifier: string;
+  requestBody: SendMimeMessageRequest;
+  queryParams: SendMimeMessageQueryParams;
+}
+
 /**
  * The parameters for the {@link Messages.listScheduledMessages} method
  * @property identifier The identifier of the grant to act upon
@@ -264,6 +278,44 @@ export class Messages extends Resource {
     return this.apiClient.request(requestOptions);
   }
 
+  /**
+   * Send an email using raw MIME format
+   * @return The sent message
+   */
+  public async sendMime({
+    identifier,
+    requestBody,
+    queryParams,
+    overrides,
+  }: SendMimeMessageParams & Overrides): Promise<NylasResponse<Message>> {
+    const path = makePathParams('/v3/grants/{identifier}/messages/send', {
+      identifier,
+    });
+
+    // Create FormData for MIME message
+    const FD = require('form-data');
+    const FormDataConstructor = FD.default || FD;
+    const form: FormData = new FormDataConstructor();
+
+    // Add MIME content
+    form.append('mime', requestBody.mime);
+
+    // Add metadata (defaults to empty string if not provided)
+    if (requestBody.metadata) {
+      form.append('metadata', requestBody.metadata);
+    }
+
+    const requestOptions: RequestOptionsParams = {
+      method: 'POST',
+      path,
+      form,
+      queryParams,
+      overrides,
+    };
+
+    return this.apiClient.request(requestOptions);
+  }
+
   /**
    * Retrieve your scheduled messages
    * @return A list of scheduled messages
diff --git a/tests/resources/messages.spec.ts b/tests/resources/messages.spec.ts
index 31714834..28b2058a 100644
--- a/tests/resources/messages.spec.ts
+++ b/tests/resources/messages.spec.ts
@@ -38,6 +38,11 @@ describe('Messages', () => {
     apiClient.request.mockResolvedValue({});
   });
 
+  beforeEach(() => {
+    jest.clearAllMocks();
+    apiClient.request.mockResolvedValue({});
+  });
+
   describe('list', () => {
     it('should call apiClient.request with the correct params', async () => {
       await messages.list({
@@ -482,6 +487,124 @@ describe('Messages', () => {
     });
   });
 
+  describe('sendMime', () => {
+    it('should call apiClient.request with the correct params for MIME message', async () => {
+      const mimeContent = `MIME-Version: 1.0
+Message-ID: <test@example.com>
+Subject: Test MIME Message
+From: sender@example.com
+To: recipient@example.com
+Content-Type: text/plain; charset="UTF-8"
+
+This is a test MIME message.`;
+
+      await messages.sendMime({
+        identifier: 'id123',
+        requestBody: {
+          mime: mimeContent,
+          metadata: 'test-metadata',
+        },
+        queryParams: {
+          type: 'mime',
+        },
+        overrides: {
+          apiUri: 'https://test.api.nylas.com',
+          headers: { override: 'bar' },
+        },
+      });
+
+      const capturedRequest =
+        apiClient.request.mock.calls[
+          apiClient.request.mock.calls.length - 1
+        ][0];
+      expect(capturedRequest.method).toEqual('POST');
+      expect(capturedRequest.path).toEqual('/v3/grants/id123/messages/send');
+      expect(capturedRequest.queryParams).toEqual({ type: 'mime' });
+      expect(capturedRequest.overrides).toEqual({
+        apiUri: 'https://test.api.nylas.com',
+        headers: { override: 'bar' },
+      });
+
+      // Check that form data was created correctly
+      const formData = (
+        capturedRequest.form as any as MockedFormData
+      )._getAppendedData();
+      expect(formData.mime).toEqual(mimeContent);
+      expect(formData.metadata).toEqual('test-metadata');
+    });
+
+    it('should use empty string for metadata when not provided', async () => {
+      const mimeContent = `MIME-Version: 1.0
+Subject: Test MIME Message
+From: sender@example.com
+To: recipient@example.com
+Content-Type: text/plain; charset="UTF-8"
+
+This is a test MIME message.`;
+
+      await messages.sendMime({
+        identifier: 'id123',
+        requestBody: {
+          mime: mimeContent,
+        },
+        queryParams: {
+          type: 'mime',
+        },
+      });
+
+      const capturedRequest =
+        apiClient.request.mock.calls[
+          apiClient.request.mock.calls.length - 1
+        ][0];
+      const formData = (
+        capturedRequest.form as any as MockedFormData
+      )._getAppendedData();
+      expect(formData.mime).toEqual(mimeContent);
+    });
+
+    it('should handle complex MIME content with multipart boundaries', async () => {
+      const mimeContent = `MIME-Version: 1.0
+Message-ID: <complex@example.com>
+Subject: Complex MIME Message
+From: sender@example.com
+To: recipient@example.com
+Content-Type: multipart/alternative; boundary="boundary_123"
+
+--boundary_123
+Content-Type: text/plain; charset="UTF-8"
+
+Plain text content
+
+--boundary_123
+Content-Type: text/html; charset="UTF-8"
+
+<div>HTML content</div>
+
+--boundary_123--`;
+
+      await messages.sendMime({
+        identifier: 'id123',
+        requestBody: {
+          mime: mimeContent,
+          metadata: 'complex-mime-test',
+        },
+        queryParams: {
+          type: 'mime',
+        },
+      });
+
+      const capturedRequest =
+        apiClient.request.mock.calls[
+          apiClient.request.mock.calls.length - 1
+        ][0];
+      const formData = (
+        capturedRequest.form as any as MockedFormData
+      )._getAppendedData();
+      expect(formData.mime).toEqual(mimeContent);
+      expect(formData.metadata).toEqual('complex-mime-test');
+    });
+  });
+
   describe('scheduledMessages', () => {
     it('listing should call apiClient.request with the correct params', async () => {
       await messages.listScheduledMessages({