Modifying Message Content Based on User Preferences

A messaging system receives a message including a recipient ID and a message body, the message body containing one or more customizable fields. The messaging system receives a user preference model based on the recipient ID. The user preference model identifies message elements and content preferred by the recipient of the message. Based on the user preference model, the messaging system modifies the customizable fields in the message body, generating a modified message. The modified message is transmitted to a client device associated with the recipient ID for presentation to the recipient.