Tocomail is an excellent site/iOS app for providing a safe email environment for children. The way this works is a child gets a free email account w/ safe/approved contacts from a guardian. Kids can then customize an avatar for their email account and even create drawings/paintings for email attachments. Parents can setup and approve a contact lists, receive quarantined emails waiting for approval, reject or approval any email, etc. Best of all, there is a content filter which quarantine the email it has any profanity and parents will be alerted if any bullying patterns are detected.
I highly recommend checking out Tocomail by clicking here!!!