For corporate mail accounts users, sending mail in webmail is commonplace. You can directly access your mail account by typing / webmail at the end of your site address. You can provide mail exchanges. To add a signature to your mail account, you need to follow the steps below.
Click on Roundcube settings.
Click the IDs field in the Settings area.
You will receive your email address. Click on your email address.
You can add your signature and other information from the field on the right.
If you want to add your signature as html click on the html box