You can add personalized signature in the mail settings = General = Personalized signature = Click html to enter the HTML editing page = Paste the code to save when QQ is online. The specific operation steps are as follows: 1, open QQ mailbox = "Settings page =" General; 2. Personalized Signature = "Add Personalized Signature =" When switching to the HTML editing page, a default code will be generated; 3. Replace the code generated on the /index.html page, and then click Save. When you send an email to a friend, your "online status" will be displayed in the column of personalized signature, so that friends who receive your email can communicate with you anytime and anywhere.

The answer comes from Tencent QQ official website.