How are you receiving your gamails and forwarding them. Is it with and web browser or are you using an email client/app?
BT can not block your gmail account from "forwarding" emails only gmail can do that.
What BT can do is block any emails from your gmail being received.
It is possible that your BT Openworld.com account, which is the same as a btinternet.com email account as both btinternet and btopenworld are interchangeable is blocking the emails from being received.
The first thing to do is check if it is your BT email account that is blocking the gmail emails.
To do that log onto your BT account using a web browser, not an email client/app, and then click on your username at the right hand side. Select "Settings" then go to the left hand side and select "Mail". Scroll down and click on "Blocked Senders".
Scroll down the list until you find the your gmail email address or gmail domain you want to unblock and select it.
Click on the small "Trash" symbol at the right hand side. It will only delete the email address from the blocked senders list not your contacts list. is blocking the gmail emails from being received.
