设置环境变量 | Set environment variables

1. Use Linux or Mac OS X bash:

export MAIL_USERNAME=<Gmail username> 
export MAIL_PASSWORD=<Gmail password>

1. Use Windows CMD:

set MAIL_USERNAME=<Gmail username> 
set MAIL_PASSWORD=<Gmail password>

1. Use Windows PowerShell:

$env: MAIL_USERNAME=<Gmail username> 
$env: MAIL_PASSWORD=<Gmail password>