Campaign Monitor

Campaign Monitor's AI Email Booster analyzes your draft campaigns and suggests improvements for subject lines, send times, and preview text based on what typically drives engagement. The AI Writer tool generates body paragraphs and calls to action when you're starting from scratch. Both features sit in the compose interface and produce suggestions you can accept, edit, or discard.

This appeals to agencies and in-house teams who want both creation and optimization help. The optimization angle sets it apart for teams that want to test and refine beyond just drafting faster.