When developing applications that need to send emails through Gmail, many developers encounter the familiar error message: *"Username and Password not accepted"*, even when they're certain their credentials are correct.

\
This occurs because Google has enhanced security for Gmail accounts, preventing "less secure apps" from accessing them directly using regular passwords. Fortunately, Google provides a more secure alternative: **App Passwords**.

\
In this article, we'll explore how to set up and use Google App Password to authenticate with Gmail's SMTP service.

## **What is an App Password?**

An App Password is a 16-character authentication code generated specifically for a particular application or device. App Passwords offer several advantages:

* **Enhanced security**: Each application gets its own distinct password, which can be individually revoked

* **Convenience**: No need to enter 2FA verification codes each time your application connects

* **Traceability**: Ability to monitor which applications are currently accessing your account

## **Prerequisites**

Before creating an App Password, you need to meet these requirements:

1. **Two-Factor Authentication (2FA)**: Your Google account must have 2FA enabled

2. **Account type**: Works with personal Google accounts or Workspace accounts (if permitted by admin)

## **Step-by-Step Guide: Setting Up Two-Factor Authentication**

If you haven't enabled 2FA yet, follow these steps:

1. **Access Google security page**: <https://myaccount.google.com/security>

2. **Locate "2-Step Verification"**

3. **Click "Get started"**

4. **Verify your identity** using your Google password

5. **Enter your phone number** and select your preferred verification method (SMS or call)

6. **Enter the verification code** sent to your phone

7. **Enable 2-Step Verification** by clicking "Turn on"

## **Creating App Password for Gmail SMTP**

After enabling 2FA, create an App Password:

1. **Access Google security page**: <https://myaccount.google.com/security>

2. **Locate "App passwords":** <https://myaccount.google.com/apppasswords>

* *Note: If this option isn't visible, you may not have enabled 2FA, your Workspace account may be restricted by admin, or you're using organizational login*

1. **Select application and device**:

* In the "Select app" field, choose "Other (Custom name)" or "Mail"

* Give it a memorable name like "SMTP Script" or "Email Service"

* Click "Create"

1. **Save the generated password**: Google will display a 16-character App Password. **Copy and save this password immediately**, as you won't be able to view it again.

## **Using App Password with Custom SMTP in Fordeer PDF Invoice**

Fordeer PDF Invoice allows you to configure custom SMTP servers for sending invoices via email. Here's a detailed guide for setting up Gmail SMTP with App Password in Fordeer PDF Invoice:

### **Step 1: Log into Fordeer PDF Invoice Admin Dashboard**

Access your Fordeer PDF Invoice application's admin dashboard and log in with your administrator credentials.

### **Step 2: Navigate to Email Settings**

1. From the main menu, select **Settings**

2. Locate and select **Email Settings** -> **Change Email Settings** -> **Customize email service**

### **Step 3: Configure SMTP with Gmail**

Fill in the Gmail SMTP information with the following parameters:

* **SMTP Server**: [`smtp.gmail.com`](https://smtp.gmail.com/)

* **SMTP Port**: `587` (or `465` if using SSL)

* **Encryption**: `TLS` (or `SSL` if using port 465)

* **Sender Name**: Display name for emails (e.g., `ABC Invoice Service`)

* **Sender Email**: Your Gmail address (e.g., [`your-email@gmail.com`](mailto:your-email@gmail.com))

* **SMTP Username**: Your full Gmail address (e.g., [`your-email@gmail.com`](mailto:your-email@gmail.com))

* **SMTP Password**: The App Password you generated from Google (without spaces)

![Using App Password with Custom SMTP in Fordeer PDF Invoice](https://chat.fordeercommerce.io/rails/active_storage/blobs/redirect/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBBZ0lDIiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--27cc59eb4028c14600342b571b14ab8d49427e97/screenshot-2025-05-12-at-15041_x2vioy.png)

### **Step 4: Test Connection and Save Settings**

1. Click the **Verify email* button to verify your configuration works

2. Enter the email you want to receive email

3. Check your email inbox

---

We value your feedback — it helps us continuously improve app and provide you with a better experience.

👉 **Chat with us:** [Share your feedback](https://chat.fordeercommerce.io/widget?website_token=w2hwvBgPjjKtbfpdE4gEH4d3#/messages) directly with our team.\
👉 **Explore more apps:** Discover more [Fordeer apps](https://apps.shopify.com/partners/fordeercommerce?utm_source=support&utm_medium=helpdesk). special deals.

🕐 **Working hours:** 8:30 AM – 5:00 PM (UTC+7), Monday–Friday. \
We typically reply to live chats within minutes and emails within a few hours. \
\
Need help? Feel free to reach out anytime via live chat or email!