Techs & Trends

The underline is probably part of the interface or font, not underline formatting applied to the text. In other words, it's only being displayed as an underline; you're not sending underline text to people. I don't think that's possible.

Could it be the keyboard / input mode you're using, like Swype or XT9? Most predictive typing systems like that will underline words as you type them just to indicate that the software is actively predicting/correcting your typing, but the underline goes away once you move on the next word.