About Outlook Conversations

What makes a conversation in Outlook?

In the Outlook world a conversation is a series of emails with the same subject line or conversation ID. It’s as simple as that. In the past these were called email ‘threads’.

Outlook 2010 and Outlook 2013 can group messages by conversation or thread.

For most people the conversation is based on the subject line. A conversation ID is a hidden property of Exchange Server 2010 and later messages. Conversations between people on the same Exchange Server system, the hidden Conversation ID message property should override the subject line.

RE: or FW: at the start of a subject line doesn’t matter so all these subject lines are considered one conversation:



  • Office-Watch.com
  • Re: Office-Watch.com
  • FW: Office-Watch.com
  • AW: Office-Watch.com
  • WG: Office-Watch.com

The last two are the German equivalents of RE and FW – other language variants are also accepted by Outlook.

Any change to the subject, beyond the ones Outlook is programmed for, means the message won’t be part of the same conversation. The following messages will NOT be part of the above conversation:



  • RE: Re: Office-Watch.com
  • Office-Watch.com is great
  • Office-Watch.com *Follow-up*
  • Office-Watch.com [SEC=UNCLASSIFIED]

The last one is an extra we’ve seen from high security organizations.

Aside from ‘RE:’ and ‘FW:’ or some equivalents it is NOT a good idea to change the subject line on an email because it will confuse the email software of the receivers (if not the receivers themselves).

If you’re wondering if messages are part of the same Outlook conversation, change the Inbox view to ‘Show as Conversations’. All messages will be grouped by conversation.

http://img.office-watch.com/ow/About%20Outlook%20Conversations.png image from About Outlook Conversations at Office-Watch.com

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