1. Enter webmail.yourdomain.com
2. Enter your email and password
3. Webmail system suggest to use "Group Webmail New"
4. Log In
Setting
Identities
Select your email account
1. Filling "Display Name"
2. Enter the message you want to show on Signature for example "Best Regards"
3. Select "HTML Signature" 和 "Set Default"
4. Save