iCloud Cannot Receive Gmail

My iCloud email account has not received any messages from Gmail users for at least a day or so. A coworker has been trying to email me, but I have not yet received any of her Gmail emails on my iCloud account. I also cannot SEND email to any Gmail user with my iCloud account. The message "sends" but they simply never receive the email. I have not received any error messages or bounce-back emails. Please advise!!!