Many users ask about editing the subject line of messages, usually because they plan to save the make the subject more better reflect the content of the message.
This is possible – and simple – just open the message, select the subject and begin typing. You don’t even need to do anything special, beyond opening the message. You can select the subject and type over it or backspace to delete all or part of the subject, or add to the subject.
After editing, click Save to commit the changes, or click close and don’t save to revert to the original subject.
You can also edit the subject when using a list view with in-cell editing enabled.
For information specific to Outlook 2010, please see Editing the Subject line in Outlook 2010.
In an Open Message
You can change the subject line of an open message. The subject appears grayed, which usually means you can’t make changes, but you can still click in the subject area and start typing.
In an Outlook View
You can make the subjects editable in the Outlook message list when in-cell editing is enabled.
Note: In Outlook 2003 and up, in-cell editing is available only when the message list is using a single line view.
Outlook 2003 and 2007: View > Current View > Customize view > Other settings button or click on the row of field names and choose Customize > Other settings.
Outlook 2002, 2000 or 98: Choose View > Current View > Customize Current View > Other Settings button
Outlook 97: Tools > Format View
You’ll see an option for Allow in-cell editing. Check that checkbox, then click OK, and you’ll be able to edit the subject of any item in the folder, without the need to open the item first.