View the original community article here
Last tested: Jul 12, 2020
The Problem
Users often come looking to change from Looker’s email service to a custom mail service. Gmail is a common choice but users run into errors during setup because certain steps haven't been followed on the Gmail/Google account end.

A broad categorisation would be Google accounts intended to be used for the custom mail service could:
- An Account with TWO-FACTOR AUTHENTICATION (2FA) enabled.
- An Account without 2FA enabled.
A Solution
- Method 1: Using an
App Password
with 2FA enabled - Method 2: Allow
Less Secure Apps
with no 2FA enabled
Screenshots have been included below to share with you as a guide
Method 1: App Password
If 2-step verification has been enabled on the account, you can generate an app password
.
Follow these steps:
- Browse to the Security Page, notice 2FA is enabled
- Or go straight to the “App passwords” page.
- Click “Select app” and choose the app you’re using.
- Click “Select device” and choose the device you’re using (In this case it would be the Looker Application).
- Click the “Generate” button.
- Enter the app password in the Admin Section >> SMTP >> custom mail settings in the Looker application.
- Click the “Done” button.







Method 2: Less Secure Apps
Depending on whether or not you use Google Apps, the steps to correct this will differ slightly.
For Google Apps Users
If you are a Google Apps user, you will need your administrator to allow users to change the policy for less secure apps. If you are a Google Apps administrator, follow these steps:
- Browse to the Google Apps administration panel.
- Click on “Security” and then “Basic settings”.
- Look for the section “Less secure apps” and then click on “Go to settings for less secure apps”.
- Select “Allow users to manage their access to less secure apps”.
For Other Google Users
If you do not use Google Apps, follow the steps in the following sections, depending on whether 2-step verification has been enabled on the account or not.
If 2-step verification has not been enabled on the account, follow these steps:
- Browse to the “Less secure apps” page and log in using the account you are having problems with. This option is typically required by many popular email clients, such as Outlook and Thunderbird, and should not be considered unsafe.
- Select the “Turn on” option.
- Enter the email credentials in the Admin Section >> SMTP >> custom mail settings in the Looker application.
- Confirm login attempt in your security prompt in the email received shortly after 1st sign-in attempt or confirm under the security checkup in the google settings page
- Once the login attempt has been acknowledged by you, you should be able to use the custom mail settings in Looker.




OR from the Google security page






Some messages that you might come across if you are following a guide other than one that matches your credential type/security settings on the Google account:
See more on The difference between Gmail, a Google Account, and G Suite account


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