!1. Google Mail OAuth 2.0\\
__Google Mail__ through __SMTP__/__IMAP__ requires __OAuth 2.0__ ([OAuth Wikipedia Link|https://en.wikipedia.org/wiki/OAuth]) for authentication. (More information : [Google IMAP-SMTP Link|https://developers.google.com/gmail/imap/imap-smtp]).\\
\\
__!!! Proxy Configuration:__ If your server accesses the internet through a proxy, make sure to whitelist the following domains for Google Mail Authentication:\\	
• oauth2.googleapis.com\\
\\
Start by navigating to Google APIs & Services: [Google APIs & Services Link|https://console.developers.google.com/projectselector/apis/credentials]\\
__!!!Note:__ Ensure sure the __GMAIL API__ is enabled at __Enabled APIs & services__. [Google API Library Link|https://console.cloud.google.com/apis/library]\\
\\
[SMTP Google Mail Integration/g_api_services.png]\\
\\
[SMTP Google Mail Integration/gmail_api_enabled.png]\\
\\
Go to the __Credentials__ menu, click on __Create Credentials__, and select __OAuth client ID__:\\
\\
[SMTP Google Mail Integration/create_credentials.png]\\
\\
Select the application type: __Web application__. Provide a unique name. Then, configure the __Authorized redirect URI__—this is where Google will redirect you after authorization. The Redirect URL must end with __?command=register_google_mail_api__.\\
\\
{{{

    http://127.0.0.1:9090/?command=register_google_mail_api
}}}\\
or
{{{
    
    https://your.crushftp.domain.com/?command=register_google_mail_api
    
}}}\\
Finally, click the __Create__ button.\\
\\
[attachments|credential_config.png]\\
\\
After the credentials are created, copy the __Client ID__ and __Client Secret__.\\
\\
[SMTP Google Mail Integration/client_id_secret.png]\\
\\
----
!2. SMTP Settings\\
\\
[SMTP Google Mail Integration/smtp_config.png]\\
\\
__SMTP Server Used for Emailing__: Enter the SMTP server address used for sending emails, such as __smtp.gmail.com__, using the default port __587__.\\
{{{
    smtp.gmail.com:587
}}}\\
\\
__SMTP Server Username, Password__: If the SMTP server address contains __office365__ or __outlook__, the corresponding __Get Refresh Token__ button will appear. Click that button to proceed.\\
__!!! Note__: To obtain the __Refresh Token__, the CrushFTP WebInterface’s host and port must match the __Redirect URL__ specified in the __Azure App Registration__. In our example, it was: http://localhost:9090 or https://your.crushftp.domain.com/\\
\\
Enter the __Client ID__ (See at App Registration -> Overview -> Application (client) ID), __Client Secret__ (See at App Registration -> Manage -> Certificates & secrets) make sure to copy the __value__ field, not the ID, and __Tenant ID__ (See at App Registration -> Overview -> Directory (tenant) ID). Proceed with the authentication and authorization process. This will automatically configure the __SMTP Server Username__ and __SMTP Server Password__.\\
\\
[attachments|oauth_form.png]\\
\\
If your domain is not verified you will get a warning message, click on Advanced and proceed further:\\ 
\\
[SMTP Google Mail Integration/not_verified_domain.png]\\
\\
Click on allow:\\
\\
[SMTP Google Mail Integration/allow_form.png]\\
\\
Once it is finished the "SMTP Server Password" input field will be filled with the refresh token.\\
\\