Change Subject Line When Replying in Gmail

Conversation threads is one of the features that we love in our Gmail. It keeps our previous messages intact allowing us to keep track on the topic at hand. However, sometimes we need to reply or forward emails with a different subject while keeping it in the same group or thread of messages. It is possible to change subject in Gmail though the feature is well hidden.
When you reply to a mail, your messages gets grouped as threads because of same subject line. At times, the topic or the mode of conversation might change and we need to change the subject of the conversation. We want to reply because it is convenient and has previous references but at the same time we want to edit subject because the topic has moved on. In such cases, we can start a new thread with new subject which will also have old messages as quoted replies.
Change Subject Line While Replying in the Same Conversation Thread
To reply or forward the emails in the same thread itself while changing the subject according to your need, just follow these simple steps-
STEP 1: Open the conversation thread. Select ‘Reply’ at the bottom of the mail. It will open a mini window for you at the bottom of the screen to type the reply.
STEP 2: Click the ‘Down’ Arrow on the top left of the message box. A drop down box will appear.
STEP 3: Select ‘EDIT SUBJECT’. A new Compose window will appear on-screen.
STEP 4: Now change the Subject as you desire and Send. The previous mails in the thread will be included with this email also.
Also remember that Gmail does not show subjects in conversation threads, so you have to keep a tab on it manually.
You can also use these steps when replying to many at the same time or forwarding the mail. Just click ‘Reply All’ or ‘Forward’ and follow the same steps.
Every time I change the subject it puts that email into a different thread. How do you keep them together?
You cannot have same email conversation thread when you change the subject line. It’s the only thing that binds the email in the thread. However, you can have same context and recipients when replying.
What if the original subject was like “Corrections required for a book” and by the end the conversation topic is completely changed? How hepfull is it that google does not allow for the subject to change now even though the conversation topic has changed I get an email with the subject RE: “Corrections required for a book” this is stupid!
Thanks for your valuable information