There are various elements you can test in an email campaign:
Subject Lines: Test different lengths, tones, and use of emojis. Email Content: Experiment with different formats, such as text vs. HTML or short vs. long content. Call to Actions (CTAs): Try different wording, button colors, and placements. Send Times: Test sending emails at different times of the day or different days of the week. Images: Use different images to see which type gets more engagement.