Mail Server

Configuring a mail server is out of scope for this documentation.

Supported SMTP Servers

- Any mainstream SMTP server will work (postfix, exim - most likely even sendmail will do)
- Testing was mostly done against postfix 3.4 - 3.7
- Horde supports TLS and STARTTLS as well as plain connections (unsecure, use only in local networks)

Supported Mail Filters

- You only need a mail filter if you use IMP webmail and the ingo filter application
- Testing was mostly done against dovecot sieve
- Cyrus Sieve and Timsieved are known to work but ancient versions cause trouble
- No testing was done for procmail. There is no obvious reason why it should not work

Supported IMAP Servers

- You need no imap server for most horde apps besides IMP webmail
- Any mainstream imap server will work (dovecot, cyrus, courier)
- testing was mostly done against dovecot 2.3
- Horde supports TLS and STARTTLS as well as plain connections (unsecure, use only in local networks)