Those that are sent in HTML or Rich Text Format which include various fonts and font sizes, bolded text, color or backgrounds sure are pretty, but they are fraught with peril. We receive calls from these users with problems that range from receiving blank messages to receiving messages with pages of garbage characters. When we investigate the problem we inevitably discover that the sender of the troublesome message spent a lot of time trying to create a formatted message that looked really nice to them, but awful to others, because other mail packages couldn't interpret the formatting.
Plain text is still better.
You just can't control how other mail packages will view your formatting. Don't use centering or bold commands. Change your mail sending format settings to plain text. You'll need to change this to Plain Text. If you are using another mail package, check the Help feature in your software or check with a technology coordinator.