Rebuild the missing context
Assume the recipient will not remember every date, promise, or earlier conversation. For a message about how to reconnect with a veterans group, use this factual base: name the group, your earlier role, why you left, and the current point of contact you found.
Say what needs to happen next
State the decision, information, or practical action you need and include a real deadline only when one exists. Ask whether rejoining or visiting is appropriate and follow the group's present process. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Avoid making urgency into pressure
Do not claim an old role, skip current rules, or pressure a volunteer to resolve historic conflict privately. Use safeguarding and formal leadership channels for discrimination, abuse, threats, or vulnerable members. Do not make the other person responsible for reducing the discomfort that prompted you to write.