Forward Mode allow users to receive mail notifications without the need to give out credential for their main Gmail account. The following are the steps to set it up:

1. Create a new Gmail account as forward account. This account is used by our application to trigger notifications. You should not use this account for other purpose. For example, create an account my_forward123@gmail.com.
2. Login into Gmail with your main account. Go to Settings->Forwarding and POP/IMAP screen, check “Forward a copy of incoming mail” and input your forward account in “email address” field. Click “Save Chages” to apply the changes. For users familiar with Filters, you can setup Filters to do forwarding.
3. Launch Gmail Push. Go to Settings screen and tap “Forward Mode”. In Forward Mode screen, turn on the switch. If your main account is a Google Apps account, you need to change the main account domain name from “gmail.com” to your domain name. Press “Back” to come back to Settings screen.
4. Come back to Gmail browser screen, input your main account name and password.