[Dovecot] Mails don't get deleted after POP3

[cullinan at rocketmail.com]

Hi, there!

Well, I am new to dovecot, so please be patient with me:

I have a virtual server and want to setup simple mail delivery.
postfix, saslauthd and dovecot basically work fine.

The only open issue is, that (I guess) dovecot doesn't remove the
mail when it's retrieved via pop3 from the server.
It keeps sending me the same emails again and again.
(The mail client (Thunderbird) is configured to remove the messages
from the server - it was working already.)

I guess that dovecot cannot write to some files / has problems
with write permissions. But it doesn't tell me anything...

Can you tell me, what configuration might be wrong or how can I
enable more debugging to see what dovecot is doing after
the mails got sent out via pop3?

Here is the configuration:

# dovecot -n
# 1.2.15: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.38-8-server x86_64 Ubuntu 11.04
log_timestamp: %Y-%m-%d %H:%M:%S
protocols: pop3 pop3s
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/pop3-login
mail_privileged_group: mail
mbox_write_locks: fcntl dotlock
mail_executable: /usr/lib/dovecot/pop3
mail_plugin_dir: /usr/lib/dovecot/modules/pop3
auth default:
   passdb:
     driver: pam
   userdb:
     driver: passwd

-----8<-----

# dovecot -a
# 1.2.15: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.38-8-server x86_64 Ubuntu 11.04
base_dir: /var/run/dovecot
log_path:
info_log_path:
log_timestamp: %Y-%m-%d %H:%M:%S
syslog_facility: mail
protocols: pop3 pop3s
listen: *
ssl_listen:
ssl: yes
ssl_ca_file:
ssl_cert_file: /etc/ssl/certs/dovecot.pem
ssl_key_file: /etc/ssl/private/dovecot.pem
ssl_key_password:
ssl_parameters_regenerate: 168
ssl_cipher_list:
ssl_cert_username_field: commonName
ssl_verify_client_cert: no
disable_plaintext_auth: yes
verbose_ssl: no
shutdown_clients: yes
nfs_check: yes
version_ignore: no
login_dir: /var/run/dovecot/login
login_executable: /usr/lib/dovecot/pop3-login
login_user: dovecot
login_greeting: Dovecot ready.
login_log_format_elements: user=<%u> method=%m rip=%r lip=%l %c
login_log_format: %$: %s
login_process_per_connection: yes
login_chroot: yes
login_trusted_networks:
login_process_size: 64
login_processes_count: 3
login_max_processes_count: 128
login_max_connections: 256
valid_chroot_dirs:
mail_chroot:
max_mail_processes: 512
mail_max_userip_connections: 10
verbose_proctitle: no
first_valid_uid: 500
last_valid_uid: 0
first_valid_gid: 1
last_valid_gid: 0
mail_access_groups:
mail_privileged_group: mail
mail_uid:
mail_gid:
mail_location:
mail_cache_fields:
mail_never_cache_fields: imap.envelope
mail_cache_min_mail_count: 0
mailbox_idle_check_interval: 30
mail_debug: no
mail_full_filesystem_access: no
mail_max_keyword_length: 50
mail_save_crlf: no
mmap_disable: no
dotlock_use_excl: yes
fsync_disable: no
mail_nfs_storage: no
mail_nfs_index: no
mailbox_list_index_disable: yes
lock_method: fcntl
maildir_stat_dirs: no
maildir_copy_with_hardlinks: yes
maildir_copy_preserve_filename: no
maildir_very_dirty_syncs: no
mbox_read_locks: fcntl
mbox_write_locks: fcntl dotlock
mbox_lock_timeout: 300
mbox_dotlock_change_timeout: 120
mbox_min_index_size: 0
mbox_dirty_syncs: yes
mbox_very_dirty_syncs: no
mbox_lazy_writes: yes
dbox_rotate_size: 2048
dbox_rotate_min_size: 16
dbox_rotate_days: 1
mail_drop_priv_before_exec: no
mail_executable: /usr/lib/dovecot/pop3
mail_process_size: 256
mail_plugins:
mail_plugin_dir: /usr/lib/dovecot/modules/pop3
mail_log_prefix: %Us(%u):
mail_log_max_lines_per_sec: 10
imap_max_line_length: 65536
imap_capability:
imap_client_workarounds:
imap_logout_format: bytes=%i/%o
imap_id_send:
imap_id_log:
imap_idle_notify_interval: 120
pop3_no_flag_updates: no
pop3_enable_last: no
pop3_reuse_xuidl: no
pop3_save_uidl: no
pop3_lock_session: no
pop3_uidl_format: %08Xu%08Xv
pop3_client_workarounds:
pop3_logout_format: top=%t/%p, retr=%r/%b, del=%d/%m, size=%s
dict_db_config:
dict_process_count: 1
managesieve_max_line_length: 65536
managesieve_logout_format: bytes=%i/%o
managesieve_implementation_string: dovecot
auth default:
   mechanisms: plain
   realms:
   default_realm:
   cache_size: 0
   cache_ttl: 3600
   cache_negative_ttl: 3600
   executable: /usr/lib/dovecot/dovecot-auth
   user: root
   chroot:
   username_chars: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@
   username_translation:
   username_format:
   master_user_separator:
   anonymous_username: anonymous
   krb5_keytab:
   gssapi_hostname:
   winbind_helper_path: /usr/bin/ntlm_auth
   failure_delay: 2
   verbose: no
   debug: no
   debug_passwords: no
   ssl_require_client_cert: no
   ssl_username_from_cert: no
   use_winbind: no
   count: 1
   worker_max_count: 30
   process_size: 256
   passdb:
     driver: pam
     args:
     deny: no
     pass: no
     master: no
   userdb:
     driver: passwd
     args:

-----8<-----

Please let me know if you need more.
Thank you in advance!

Regards,

Rob