# Fixes you need after upgrading Debian from 8 to 9

## Postfix

Run commands:

    # Backup files
    cp /etc/postfix/main.cf /etc/postfix/main.cf.bak
    cp /etc/postfix/master.cf /etc/postfix/master.cf.bak

    # Update main.cf and master.cf
    postconf -e daemon_directory='/usr/lib/postfix/sbin'
    postconf -e shlib_directory='/usr/lib/postfix'
    postconf -e compatibility_level=2
    for i in $(postconf -Mf | grep '^[0-9a-zA-Z]' | awk '{print $1"/"$2"/chroot=n"}'); do postconf -F $i; done

- Incorrect `daemon_directory` causes Postfix cannot start.
- Incorrect `shlib_directory` causes Postfix cannot find pcre/mysql/pgsql/ldap modules.
- Debian 8 ships Postfix 2.x, but Debian 9 ships Postfix 3.x, we need to disable compatible mode.

## Dovecot

Please remove `!SSLv2` from parameter `ssl_protocols`, and restart Dovecot service:

    ssl_protocols = !SSLv3

## Fail2ban

There's a duplicate parameter in file `/etc/fail2ban/jail.conf`, under section `[pam-generic]` like below:

    [pam-generic]
    ...
    port = all
    ...
    port = anyport

Comment out `port = anyport` and restart fail2ban service.