Keep the thread.

1. Most outreach goes wrong between messages. The follow-up starts a new email instead of continuing the conversation. A reply sits unnoticed. A list drifts out of date.
2. Keeping contacts and outreach in order means one record per person and one thread per conversation, from the first message to the last, with each follow-up waiting its turn and stopping as soon as the other person writes back.
3. crm-contacts is coming soon.