diff --git a/firestore-send-email/functions/__tests__/nodemailer-sendgrid/index.test.ts b/firestore-send-email/functions/__tests__/nodemailer-sendgrid/index.test.ts
index 3ec2c7753..bab3e3445 100644
--- a/firestore-send-email/functions/__tests__/nodemailer-sendgrid/index.test.ts
+++ b/firestore-send-email/functions/__tests__/nodemailer-sendgrid/index.test.ts
@@ -408,6 +408,62 @@ describe("SendGridTransport", () => {
     });
   });
 
+  test("send: forwards customArgs object", async () => {
+    const transport = new SendGridTransport({ apiKey: "KEY" });
+    const fakeMail: any = {
+      normalize: (cb: any) =>
+        cb(null, {
+          from: { address: "a@x.com" },
+          to: [{ address: "b@x.com" }],
+          subject: "Custom args test",
+          customArgs: { campaign: "welcome", source: "signup" },
+        }),
+    };
+    const cb = jest.fn();
+
+    transport.send(fakeMail, cb);
+    await new Promise((r) => setImmediate(r));
+
+    const sent = (sgMail.send as jest.Mock).mock.calls[0][0];
+    expect(sent.customArgs).toEqual({ campaign: "welcome", source: "signup" });
+    expect(cb).toHaveBeenCalledWith(null, {
+      messageId: null,
+      queueId: "test-message-id",
+      accepted: ["b@x.com"],
+      rejected: [],
+      pending: [],
+      response: "status=202",
+    });
+  });
+
+  test("send: forwards ipPoolName string", async () => {
+    const transport = new SendGridTransport({ apiKey: "KEY" });
+    const fakeMail: any = {
+      normalize: (cb: any) =>
+        cb(null, {
+          from: { address: "a@x.com" },
+          to: [{ address: "b@x.com" }],
+          subject: "IP pool test",
+          ipPoolName: "transactional",
+        }),
+    };
+    const cb = jest.fn();
+
+    transport.send(fakeMail, cb);
+    await new Promise((r) => setImmediate(r));
+
+    const sent = (sgMail.send as jest.Mock).mock.calls[0][0];
+    expect(sent.ipPoolName).toEqual("transactional");
+    expect(cb).toHaveBeenCalledWith(null, {
+      messageId: null,
+      queueId: "test-message-id",
+      accepted: ["b@x.com"],
+      rejected: [],
+      pending: [],
+      response: "status=202",
+    });
+  });
+
   test("send: deduplicates and normalizes email addresses", async () => {
     const transport = new SendGridTransport();
     const source = {
diff --git a/firestore-send-email/functions/__tests__/validation.test.ts b/firestore-send-email/functions/__tests__/validation.test.ts
index 1d74fca27..e54990b3c 100644
--- a/firestore-send-email/functions/__tests__/validation.test.ts
+++ b/firestore-send-email/functions/__tests__/validation.test.ts
@@ -212,6 +212,28 @@ describe("validatePayload", () => {
     });
   });
 
+  it("should validate a SendGrid payload with customArgs", () => {
+    const validPayload = {
+      to: "test@example.com",
+      sendGrid: {
+        templateId: "d-template-id",
+        customArgs: { campaign: "welcome", source: "signup" },
+      },
+    };
+    expect(() => validatePayload(validPayload)).not.toThrow();
+  });
+
+  it("should validate a SendGrid payload with ipPoolName", () => {
+    const validPayload = {
+      to: "test@example.com",
+      sendGrid: {
+        templateId: "d-template-id",
+        ipPoolName: "transactional",
+      },
+    };
+    expect(() => validatePayload(validPayload)).not.toThrow();
+  });
+
   it("should validate a SendGrid payload with only mailSettings", () => {
     const validPayload = {
       to: "test@example.com",
@@ -255,6 +277,26 @@ describe("validatePayload", () => {
       );
     });
 
+    it("should throw ValidationError for SendGrid customArgs with non-string values", () => {
+      const invalidPayload = {
+        to: "test@example.com",
+        sendGrid: {
+          customArgs: { campaign: 123 },
+        },
+      };
+      expect(() => validatePayload(invalidPayload)).toThrow(ValidationError);
+    });
+
+    it("should throw ValidationError for SendGrid ipPoolName with non-string value", () => {
+      const invalidPayload = {
+        to: "test@example.com",
+        sendGrid: {
+          ipPoolName: 123,
+        },
+      };
+      expect(() => validatePayload(invalidPayload)).toThrow(ValidationError);
+    });
+
     it("should throw ValidationError for custom template without name", () => {
       const invalidPayload = {
         to: "test@example.com",
diff --git a/firestore-send-email/functions/src/index.ts b/firestore-send-email/functions/src/index.ts
index 1611a051e..97cc48e09 100644
--- a/firestore-send-email/functions/src/index.ts
+++ b/firestore-send-email/functions/src/index.ts
@@ -179,6 +179,8 @@ async function deliver(ref: DocumentReference): Promise<void> {
       templateId: payload.sendGrid?.templateId,
       dynamicTemplateData: payload.sendGrid?.dynamicTemplateData,
       mailSettings: payload.sendGrid?.mailSettings,
+      customArgs: payload.sendGrid?.customArgs,
+      ipPoolName: payload.sendGrid?.ipPoolName,
     };
 
     logs.info("Sending via transport.sendMail()", { mailOptions });
diff --git a/firestore-send-email/functions/src/nodemailer-sendgrid/index.ts b/firestore-send-email/functions/src/nodemailer-sendgrid/index.ts
index 9d7d24c78..e02807aa3 100644
--- a/firestore-send-email/functions/src/nodemailer-sendgrid/index.ts
+++ b/firestore-send-email/functions/src/nodemailer-sendgrid/index.ts
@@ -152,6 +152,12 @@ export class SendGridTransport {
           case "mailSettings":
             msg.mailSettings = source.mailSettings;
             break;
+          case "customArgs":
+            msg.customArgs = source.customArgs;
+            break;
+          case "ipPoolName":
+            msg.ipPoolName = source.ipPoolName;
+            break;
 
           default:
             msg[key] = source[key];
diff --git a/firestore-send-email/functions/src/nodemailer-sendgrid/types.ts b/firestore-send-email/functions/src/nodemailer-sendgrid/types.ts
index f8e6e626c..3f7ed10c5 100644
--- a/firestore-send-email/functions/src/nodemailer-sendgrid/types.ts
+++ b/firestore-send-email/functions/src/nodemailer-sendgrid/types.ts
@@ -46,6 +46,8 @@ export interface MailSource {
   templateId?: string;
   dynamicTemplateData?: Record<string, unknown>;
   mailSettings?: Record<string, unknown>;
+  customArgs?: Record<string, string>;
+  ipPoolName?: string;
 
   [key: string]: unknown;
 }
@@ -91,5 +93,7 @@ export interface SendGridMessage {
   templateId?: string;
   dynamicTemplateData?: Record<string, unknown>;
   mailSettings?: Record<string, unknown>;
+  customArgs?: Record<string, string>;
+  ipPoolName?: string;
   [key: string]: unknown;
 }
diff --git a/firestore-send-email/functions/src/types.ts b/firestore-send-email/functions/src/types.ts
index e03e74e74..1b476fb23 100644
--- a/firestore-send-email/functions/src/types.ts
+++ b/firestore-send-email/functions/src/types.ts
@@ -86,6 +86,8 @@ export interface QueuePayload {
     templateId?: string;
     dynamicTemplateData?: { [key: string]: any };
     mailSettings?: { [key: string]: any };
+    customArgs?: Record<string, string>;
+    ipPoolName?: string;
   };
   to: string[];
   toUids?: string[];
@@ -127,4 +129,6 @@ export interface ExtendedSendMailOptions extends nodemailer.SendMailOptions {
   templateId?: string;
   dynamicTemplateData?: Record<string, any>;
   mailSettings?: Record<string, any>;
+  customArgs?: Record<string, string>;
+  ipPoolName?: string;
 }
diff --git a/firestore-send-email/functions/src/validation.ts b/firestore-send-email/functions/src/validation.ts
index 0d13af707..98f4e4ca7 100644
--- a/firestore-send-email/functions/src/validation.ts
+++ b/firestore-send-email/functions/src/validation.ts
@@ -93,6 +93,8 @@ const sendGridSchema = z
     templateId: z.string().optional(),
     dynamicTemplateData: z.record(z.any()).optional(),
     mailSettings: z.record(z.any()).optional(),
+    customArgs: z.record(z.string()).optional(),
+    ipPoolName: z.string().optional(),
   })
   .refine(
     (data) => {