Think about who will receive your email, and incorporate language (think about your tone and copy) that'll resonate with them the best. For example, if you're targeting CTO’s, highlight pain points of cyber attacks and how CTO’s need to learn more about the cybersecurity solutions at your trade show booth.
Pro tip: include a link to a piece of your content (that relates to the event) that you think recipients will be interested in.
In addition to thinking about your target audience, tailor the copy to the event itself, too. If the purpose of the event is to socialize and entertain, keep the copy light and fun. If the event is more professional, communicate its educational and networking value with a more serious tone.