Conversation View

Question

Conversation View

Melanie Gray 0

Does Replying after an email has been Forwarded create a new thread? See below example.

OG Subject Line - "Hunter AL Flooring"

Forward - "Fwd: Hunter AL Flooring"

Reply - "Re: Fwd: Hunter AL Flooring"

0 comments

1 answer

Your answer

Answer 1

Kai-L 13,705 Microsoft External Staff Moderator

Dear @Melanie Gray,

Thank you for reaching out to Microsoft Q&A forum.

To answer your question, it depends on whether you’ve enabled "group messaging by conversation" in your email settings. While the subject line does change by adding "Fwd:" or "Re:", modern email clients like Outlook and Gmail use hidden headers (such as "Message-ID" and "In-Reply-To") to keep these emails grouped together. Here's how the threading works:

When you group messages by conversation:

Outlook will typically keep the "Fwd:" and "Re:" versions in the same thread.
Outlook recognizes them as part of the same original chain by looking at the Thread-Index header. Even though the subject line changes from "Hunter AL Flooring" to "Re: Fwd: Hunter AL Flooring," the software still identifies them as part of the same thread.
As a result, all three emails will be nested under a single line in your inbox.

When you don’t group messages by conversation:

Each step in your example will appear as a separate, individual email.
The messages will be sorted by the time they were received, and their relationship to each other is ignored.
You will see three distinct entries in your inbox, likely appearing one after the other.

I hope this answers your question. If you have any more questions or need further assistance, please don’t hesitate to reach out. I’m always here to help. Have a wonderful day!

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Melanie Gray 0 Reputation points

2026-03-05T22:08:14.8933333+00:00

I have them grouped by conversation but am still getting replies from people that start a new thread even when the only part of the subject line is like my original example.
Kai-L 13,705 Reputation points Microsoft External Staff Moderator

2026-03-05T22:51:30.5966667+00:00

Dear @Melanie Gray,
Thank you for your update. In that case, it's possible that the In-Reply-To header, which references your original message ID, has been stripped away or broken. This can sometimes happen when the sender adds tags, forwards the email to a third person, or uses a different email client that handles threading differently.

I tried to replicate the issue on my end, but everything appears to be working as expected. Do you experience this issue with every email, or is it only happening with this specific sender?
Melanie Gray 0 Reputation points

2026-03-05T23:39:26.67+00:00

I did not know this could happen if they tag the emails. Can you explain how adding tags impacts this?
Kai-L 13,705 Reputation points Microsoft External Staff Moderator

2026-03-08T15:50:31.0433333+00:00
Dear @Melanie Gray,
Thank you for your update. From my research, tags often indicate that the email has passed through a "gateway" (a security or routing server).

This means that these gateways sometimes generate a brand-new Conversation ID for the message to track it through their own system.

When that email arrives back in your inbox, its metadata suggests it is the start of a new conversation tree, overriding the text-based matching Outlook usually performs.

I hope this answers your question. Please let me know if you need any further assistance.

Share via

Conversation View

1 answer

Your answer