The Horde replaced Mailsite Express. Mailsite Express is not available.
This new system has modern features.
Please find the contacts details from the old system in the "Contacts" folder. To view or use one, click on a name. To send an email, click on the email address and that will open a new window.
The new address book system will remember your contacts in "Favourite" section automatically, or you can add addresses to it manually.