Many want to ability to have the visual cue that indicates that they have either replied or forwarded an email. Unfortunately, GMail does not automatically provide such a cue but you can craft one by using labels. Here’s how:
Go to Settings and select Filters and Blocked Addresses
Click Create New Filter in blue in the middle of the screen
In the next dialogue box, fill in only the two boxes as below:
From: (your email address: username@nist.ac.th)
Subject: Re:
Click continue
The next dialogue box begins with “When a message arrives that matches this search:”
Click the tick box “Apply the label:” and create a new label named REPLIED
To change the colour of the label, visit the labels (similar to folders) list on the left and either right click, ctrl click, or hover over the label to see the drop down triangle on the right. Select the top item “Label Colour” and pick the colour you prefer.
Repeat the above instructions for forwarded emails by changing the Subject to Fwd:
NOTE: This only works while using Conversation View. Change this in the General settings.