Want your follow-up emails to appear in the same email thread as your first message?
This guide shows you exactly how to set up your sequence so recipients see one clean conversation in their inbox.
Learning Objective
By the end of this tutorial, you’ll know how to keep follow-up emails threaded with your first email by configuring subject lines correctly in your lemlist sequence.
Why This Matters
Threaded follow-ups look more natural, reduce inbox clutter, and make it easier for prospects to understand the context. In many inboxes, this can also improve engagement because the conversation history stays in one place.
Prerequisites
You already have a sequence with at least two Email steps.
Your sending email account is connected (or you know which sender you’ll use for the sequence).
Core Lesson — Step-by-Step Workflow
Phase 1: Set the threading rule (subject lines)
Add a subject line to Email Step 1.
Your first email subject becomes the “parent” subject that follow-up emails reuse for threading. Open your first email step and enter the subject line in the Subject line field.
For every follow-up Email step (Step 2, Step 3, etc.), keep the threaded subject unchanged.
Follow-up email steps now display the inherited threaded subject automatically. You’ll also see a warning that changing the subject line will break the email thread. If you want to keep emails in the same thread, do not edit this subject.
If needed, you can still change it by clicking the little pen icon next to the subject line, but this will break the existing thread and send the follow-up as a separate conversation.
Phase 2: Confirm the key settings that can break threading
Use the same sender for the full thread.
If you switch senders between steps, some email providers may treat follow-ups as a separate conversation. Exception: if you use a forced sender with Thread behavior set to Reply, lemlist keeps the forced-sender step inside the existing thread despite the sender change.
Avoid adding CC/BCC on threaded sequences.
In some providers (like Gmail or Outlook), adding CCs or BCCs can cause the follow-up to split into a new thread. Note: when using a forced sender in Reply mode, lemlist adds both senders as CC automatically — this is by design and does not break threading.
Practical Application / Real-Life Example
Here’s a simple 2-step example that stays threaded:
Email Step 1: Subject = “Quick question about
{{companyName}}Email Step 2 (follow-up): Uses the inherited threaded subject automatically
Result: recipients typically see Email Step 2 as part of the same conversation with Email Step 1.
Troubleshooting & Pitfalls
Issue: Follow-ups appear as separate threads in the recipient’s inbox
Root cause: The follow-up step’s inherited subject was changed.
Fix: Keep the automatically inherited subject unchanged on Email Step 2+.
Issue: Some follow-ups thread, but others don’t
Root cause: Sender changes between steps or CC/BCC is used on certain steps.
Fix: Keep the same sender on all steps and remove CC/BCC for that sequence. If you intentionally want a different sender on one step, enable Override sender on that step and set Thread behavior to Reply to stay in the same thread.
Issue: Messages look separate in lemlist (Outbox / dashboard)
Root cause: lemlist may display steps as separate sends for tracking and reporting.
Fix: Check your inbox view (recipient side). Recipients usually still see one threaded conversation when the follow-up keeps the inherited subject unchanged.