Keep your AI agent's email replies in the right thread

Short summary

Email threading in AI agents requires Message-ID, In-Reply-To, and References headers—not subject lines—to keep conversations together. Nylas API handles header management automatically for API sends, SMTP submissions, and inbound mail. Implement via reply_to_message_id, SMTP with preserved headers, or the Threads API to maintain conversation context and keep agents credible.

• •Subject-line matching fails in production; use email headers (Message-ID, In-Reply-To, References) instead
• •Nylas API automates header management on API sends, SMTP submissions, and inbound messages
• •Use reply_to_message_id parameter or Threads API to fetch conversation history before agent responds

Generated with AI, which can make mistakes.