Installing Horde on Debian Jessie

Starting with base system installed.
Install the Email server (MTA):
We need a working mail system, here we use sendmail with dovecot providing IMAP:
 apt-get install sendmail

Configure domain & SMTP settings:
 nano /etc/mail/local-host-names
   mydomain.com
 nano /etc/sendmail.mc
   MASQUERADE_DOMAIN(mydomain.com)
 make -C /etc/mail
 /etc/init.d/sendmail reload

Install an IMAP provider:
 apt-get install dovecot-imapd
Allow plaintext authentication temporarily (or configure TLS certificate?):
 nano /etc/mail/...
Test a local user authentication:
 telnet 143
 a login
 b select inbox

Install the web server:
 apt-get install apache2

Install the database server:
There are no instructions or guides explaining how to use sqlite, so we will use postgresql since it has fewer dependencies than mysql. We need to create a user and a blank database that will be used by Horde.
 apt-get install postgresql
  su - postgres
  psql
  ALTER USER horde PASSWORD 'new-password';
  CREATE horde
  \q
Test the new postgresql user:

psql -U horde -W 

Install Horde:
 apt-get install php-horde-webmail
 apt-get install php5-postgres
 webmail-install
 cd /etc/horde/imp
 cp backends.php backends.local.php
 nano backends.local.php
  (remove unnecessary lines)
  (change the imap 'secure' setting from 'tls' to 'no security')
 /etc/init.d/apache2 restart

Try to log in via web interface, using a local user account:
 http://server/horde/

Create an Administrator:
 ???
*Debian php-horde includes a script at /usr/share/php/data/horde/scripts/sql
that sets an Administrator user, but it's use is not documented.

Try to access the admin site:
 http://server/horde/admin/config

Enable SMTP
Set up the receive domain:
 nano /etc/mail/local-host-names
   mydomain.com

Set up the email address aliases:
 nano /etc/mail/aliases
  aliasname: username

Enable SMTP daemon to listen on all IP addresses:
 nano /etc/mail/sendmail.mc
   DAEMON_OPTIONS(`Family=inet,  Name=MTA-v4, Port=smtp, Addr=0.0.0.0')dnl

 /etc/init.d/sendmail restart