[horde] Help with Horde Groupware install

[Tom Faigle]

Hello everyone I'm new and trying to get a mail server and Horde Groupware
running.

I've gone through all of the documentation, and have the server (CentOS 7)
working with a Mariadb database.

Everything looks ok except that the users aren't able to connect to the
mail system and get the following message: User tfaigle is not authorized
for Mail (Host:ip.xxx.xxx.xxx)

Could someone please tell me how to adjust my configuration so that my
users will connect to the mail server and be able to use mail via Horde
Groupware 5.2.11 or at least point me to a good document that tells me
which configuration files, and what I need to do?

I hate to ask, but I'm at a loss.  It's been a long time since I've setup a
Linux server so if I'm missing something I apologize in advance.  And thank
you all for your help in advance also.

Tom