Each email client has its own font rendering engine. Although they all have a number of default fonts, each font differs between clients. If a font is not installed on a subscriber's device, it will not render correctly and switch to a default font.
To minimize the risk of this outcome, we suggest using email-safe fonts in your messages. We do not recommend using bold text. We suggest using large font sizes for titles and italics to emphasize words.
Outlook has a fall back fail-safe for certain email-safe fonts. Any font in the font family with inverted commas gets stripped and replaced with Times New Roman. We suggest that font families with a font in inverted commas, be placed second in the list.