Here are a few tips to help your emails display properly on different devices:

1. Use relative font sizes (e.g., em and rem units) instead of absolute font sizes (e.g., pt and px units).
2. Avoid using tables for formatting email and instead use CSS-based formatting.
3. Ensure that the text size of your email can be resized to fit different devices.
4. Set a maximum width for your email layout.
5. Be aware that some email clients may strip media queries or embedded CSS.