I have tried configuring a Postfix/Dovecot combo with virtual users using this guide.
My server is running Postfix 2.6.6 and Dovecot 2.0.9 on CentOS 6.5.
The problem is that when I connect to the server using Outlook 2013 (it connects just fine on IMAP+SMTP) and send myself a test e-mail I don't receive the e-mail. Looking at the maillog I can see I'm getting the error
postfix/virtual[2768]: 9C3D480768: to=<user@domain.net>, relay=virtual, delay=1132, delays=1132/0.02/0/0.02, dsn=4.2.0, status=deferred (delivery failed to mailbox /var/vmail/domain.net/user: cannot open file: Is a directory)
The error message was pretty clear and I thought, well, this could be leftovers from a defect Cyrus/Postfix installation I had earlier. I went ahead and deleted the vmail folder, created a subfolder for the domain and changed the ownership of everything to vmail:vmail. I restart postfix and dovecot and the inbox directory appears again. Postfix continues to complain as it did before. Then I tried deleting the folder and then create an empty file, but this only made it a dovecot issue rather than a postfix issue, so now dovecot says it was expecting a file rather than a directory.
/etc/postfix/main.cf
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
unknown_local_recipient_reject_code = 550
alias_maps = hash:/etc/postfix/aliases
alias_database = $alias_maps
inet_interfaces = all
inet_protocols = ipv4
mydestination = $myhostname, localhost.$mydomain, localhost
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.6.6/samples
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
relay_domains = *
virtual_alias_maps=hash:/etc/postfix/vmail_aliases
virtual_mailbox_domains=hash:/etc/postfix/vmail_domains
virtual_mailbox_maps=hash:/etc/postfix/vmail_mailbox
virtual_mailbox_base = /var/vmail
virtual_minimum_uid = 2222
virtual_transport = virtual
virtual_uid_maps = static:2222
virtual_gid_maps = static:2222
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = /var/run/dovecot/auth-client
smtpd_sasl_security_options = noanonymous
smtpd_sasl_tls_security_options = $smtpd_sasl_security_options
smtpd_sasl_local_domain = $mydomain
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
/etc/dovecot/dovecot.conf
listen = *
ssl = no
protocols = imap lmtp
disable_plaintext_auth = no
auth_mechanisms = plain login
mail_access_groups = vmail
default_login_user = vmail
first_valid_uid = 2222
first_valid_gid = 2222
mail_location = maildir:/var/vmail/%d/%n
passdb {
driver = passwd-file
args = scheme=SHA1 /etc/dovecot/passwd
}
userdb {
driver = static
args = uid=2222 gid=2222 home=/var/vmail/%d/%n allow_all_users=yes
}
service auth {
unix_listener auth-client {
group = postfix
mode = 0660
user = postfix
}
user = root
}
service imap-login {
process_min_avail = 1
user = vmail
}
and finally some example entries in my domains/aliases/mailbox lists
domain.tld OK # /etc/postfix/vmail_domains
user@domain.tld domain.tld/user # /etc/postfix/vmail_mailbox
user@domain.tld user@domain.tld # /etc/postfix/vmail_aliases
user@domain.tld:oOeIaLM/TyEPOdflb+GlL7d1MhE= # /etc/dovecot/passwd
