Help wiht Postfix and dovecot

Dear people,

I hope you can give me a hand on this. I am trying to learn about linux. I want to setup a simple solution with postfix and dovecot, eg using text files for users and passwords. I want to do this with virtual users and virtual domains. For now i am on setting up a mail server. I have postfix running and i am able to send emails. My next step is dovecot. I thought i had it all but when trying to login it fails to authenticate.

in the message log i have this entry.

dovecot: Oct 26 19:22:45 Info: auth(default): passwd-file([email protected],::ffff:xxx.xxx.xxx.xxx): no passwd file: username_format=user /var/mail/vhosts/domain.com/shadow

I have a hard time to understand the relationship between userdb, passdb and shadow if someone could direct me to an article or maybe recommend a book i would be greatful

Thanks in advance

 

If you're using system users, Dovecot should look up the passwords in /etc/shadow.

 

This is my dovecot.conf file


log_path: /var/log/dovecot.log
info_log_path: /var/log/dovecot-info.log
ssl_disable: yes
verbose_ssl: yes
login_dir: /var/run/dovecot/login
login_executable(default): /usr/libexec/dovecot/imap-login
login_executable(imap): /usr/libexec/dovecot/imap-login
login_executable(pop3): /usr/libexec/dovecot/pop3-login
mail_location: maildir: /var/mail/vhosts/%d/%n
mail_debug: yes
mail_executable(default): /usr/libexec/dovecot/imap
mail_executable(imap): /usr/libexec/dovecot/imap
mail_executable(pop3): /usr/libexec/dovecot/pop3
mail_plugin_dir(default): /usr/lib64/dovecot/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/pop3
auth default:
mechanisms: plain login CRAM-MD5
verbose: yes
debug: yes
debug_passwords: yes
passdb:
driver: passwd-file
args: username_format=%n /var/mail/vhosts/%d/shadow
userdb:
driver: passwd-file
args: username_format=%n /var/mail/vhosts/%d/passwd
userdb:
driver: passwd
socket:
type: listen
client:
path: /var/spool/postfix/private/auth
mode: 432


I am trying to setup virtual users and domains.

What is the difference between these two settings

passdb passwd-file {
}

userdb passwd-file {
}

Thanks in advance