In order to check your Gmail (VU Email Account) storage limit, please follow the steps given below.
Please check your storage limit at the bottom of Gmail page.
If you approach your storage limit, the quota indicator will change from green to red.
If you go over your limit, incoming messages to your account will be returned to the sender.
If you've hit your limit and need to clear space, you'll need to move messages to Trash and permanently delete them from there.
To move a message to Trash:
Select or open the message.
Click the Delete button.
To permanently delete a specific message:
Click Trash along the left side of any Gmail page. (If you don't see Trash along the left side of your Gmail page, go to the Labels tab in Settings, then click the show link next to the Trash label.)
Select the message you'd like to delete.
Click Delete Forever.
To permanently delete all of the messages in your Trash at once:
Click Trash. (If you don't see Trash along the left side of your Gmail page, go to the Labels tab in Settings, then click the show link next to the Trash label.)
Click Empty Trash now.
Click OK to confirm and delete all messages.
Messages left in Trash for 30 days will be permanently deleted automatically. Messages that are permanently deleted, manually or automatically, cannot be recovered.