Keep the message proportionate
Use the shortest explanation that still tells the truth about the event, impact, and current position. For a message about how to reconnect with a former professor, use this factual base: remind the person where you worked together, when, and what current topic makes the contact relevant.
Give timing that can be trusted
Give a realistic date, a simple option, or a direct yes-or-no question and avoid vague promises such as soon. Make one modest request and give enough information for them to decline or redirect it. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Close the loop without drama
Do not imply endorsement, exploit a former hierarchy, or send confidential material from the old relationship. Use official business, privacy, conflict, and procurement rules when commercial or regulated information is involved. A calm ending is more credible than a warning, a grand gesture, or language designed to provoke a response.