dovecot - Mar 2010 - Mbox corruption - Inbox beginning with 'FFrom' or 'FrFrom'

Hi,

Since the 23rd of March, we encounter mailbox corruption for some users 
(15 out of 5000) using POP mainly via Thunderbird.
Symptoms are :

    -users can login but fail to receive new mails and fail to read 
their inbox
    -Dovecot.log : ar 29 11:00:06 Error: POP3(user_login): Couldn't init 
INBOX: Mailbox isn't a valid mbox
    -The mailbox start with either 'FFrom or 'FrFrom'

We can temporarily fix the issue by manually editing the mailbox so that 
it begins with a proper 'From'.
For some users, the problem reoccurred after we apply this workaround.
I have to mention that this server has been running fine since almost a 
year with the current  hardware and software configuration.

Does anybody has an idea regarding this issue?

Many thanks

Henri

============================System :        openSUSE 11.1 (x86_64)
Local FS :     ReiserFS

dovecot -n
# 1.1.7: /etc/dovecot/dovecot.conf
# OS: Linux 2.6.27.37-0.1-default x86_64 openSUSE 11.1 (x86_64)
log_path: /var/log/dovecot.log
syslog_facility: local7
protocols: imap imaps pop3 pop3s managesieve
listen(default): *
listen(imap): *
listen(pop3): *
listen(managesieve): *:2000
ssl_cert_file: /etc/ssl/certs/cert_742088754.pem
ssl_key_file: /etc/ssl/private/imap.ehess.fr.key
disable_plaintext_auth: no
verbose_ssl: yes
login_dir: /var/run/dovecot/login
login_executable(default): /usr/lib/dovecot/imap-login
login_executable(imap): /usr/lib/dovecot/imap-login
login_executable(pop3): /usr/lib/dovecot/pop3-login
login_executable(managesieve): /usr/lib/dovecot/managesieve-login
login_greeting_capability(default): yes
login_greeting_capability(imap): yes
login_greeting_capability(pop3): no
login_greeting_capability(managesieve): no
mail_max_userip_connections(default): 10
mail_max_userip_connections(imap): 10
mail_max_userip_connections(pop3): 3
mail_max_userip_connections(managesieve): 10
mail_uid: mail
mail_gid: mail
mail_location: mbox:~/:INBOX=/var/mail/%u:INDEX=/var/run/dovecot/indexes/%n
mbox_lazy_writes: no
mail_executable(default): /usr/lib/dovecot/imap
mail_executable(imap): /usr/lib/dovecot/imap
mail_executable(pop3): /usr/lib/dovecot/pop3
mail_executable(managesieve): /usr/lib/dovecot/managesieve
mail_plugins(default): quota imap_quota trash expire
mail_plugins(imap): quota imap_quota trash expire
mail_plugins(pop3): quota
mail_plugins(managesieve):
mail_plugin_dir(default): /usr/lib64/dovecot/modules/imap
mail_plugin_dir(imap): /usr/lib64/dovecot/modules/imap
mail_plugin_dir(pop3): /usr/lib64/dovecot/modules/pop3
mail_plugin_dir(managesieve): /usr/lib64/dovecot/modules/managesieve
imap_client_workarounds(default): outlook-idle delay-newmail
imap_client_workarounds(imap): outlook-idle delay-newmail
imap_client_workarounds(pop3):
imap_client_workarounds(managesieve):
pop3_reuse_xuidl(default): no
pop3_reuse_xuidl(imap): no
pop3_reuse_xuidl(pop3): yes
pop3_reuse_xuidl(managesieve): no
pop3_lock_session(default): no
pop3_lock_session(imap): no
pop3_lock_session(pop3): yes
pop3_lock_session(managesieve): no
pop3_client_workarounds(default):
pop3_client_workarounds(imap):
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
pop3_client_workarounds(managesieve):
dict_db_config: /etc/dovecot/dovecot-db.conf
sieve_storage(default):
sieve_storage(imap):
sieve_storage(pop3):
sieve_storage(managesieve): ~/sieve
sieve(default):
sieve(imap):
sieve(pop3):
sieve(managesieve): ~/.dovecot.sieve
auth default:
  mechanisms: plain login
  verbose: yes
  debug: yes
  passdb:
    driver: pam
    args: dovecot
  userdb:
    driver: passwd
  socket:
    type: listen
    client:
      path: /var/run/dovecot/auth-client
      mode: 432
    master:
      path: /var/run/dovecot/auth-master
      mode: 384
plugin:
  quota: fs:User quota:user:mount=/var/spool/mail
  quota_rule: *:storage=40M
  quota_rule2: INB0X:storage=250M
  quota_rule3: Trash:storage=20M
  quota_rule4: Spam:ignore
  quota_rule4: Sent:storage=20M
  trash: /etc/dovecot/dovecot-trash.conf
  expire: Trash 7 Spam 1
  expire_dict: proxy::expire
dict:
  expire: db:/var/lib/dovecot/expire.db

On Tue, 2010-03-30 at 14:56 +0200, Henri Khou wrote:
>     -Dovecot.log : ar 29 11:00:06 Error: POP3(user_login): Couldn't
init
> INBOX: Mailbox isn't a valid mbox
>     -The mailbox start with either 'FFrom or 'FrFrom'
I haven't seen these since v0.99. Are you using also Dovecot deliver? Is
anything else than Dovecot modifying the mbox files? I don't really have
any great ideas, other than some locking problem if something besides
Dovecot does changes..

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> >     -Dovecot.log : Mar 29 11:00:06 Error: POP3(user_login):
 > >        Couldn't init INBOX: Mailbox isn't a valid mbox
 > >     -The mailbox start with either 'FFrom or 'FrFrom'
 >
 > I haven't seen these since v0.99. Are you using also Dovecot
 > deliver? Is anything else than Dovecot modifying the mbox
 > files? I don't really have any great ideas, other than some
 > locking problem if something besides Dovecot does changes..

We're having the same issues on our servers here and it
oddly started at exactly the same time (March 20th or so)
with no changes made by us.

We've upgraded to the latest Dovecot 1.2.11 and are using
Dovecot 'deliver' exclusively.  Tried setting
fsync_disable=no, but the problem persists.  It seems to
only occur for mailboxes that are being accessed via POP3
and leaving mail on the server.

Any further insights?  I'm surprised more people aren't
experiencing this problem.  I don't think we're doing anything 
particularly special.

Thanks,
Erik

----

# 1.2.11: /etc/postfix/dovecot.conf
# OS: FreeBSD 7.2-STABLE i386
base_dir: /var/run/dovecot
protocols: imap imaps pop3 pop3s
ssl_cert_file: sslcert.pem
ssl_key_file: sslcert.pem
ssl_cipher_list: 
ALL:!aNULL:!ADH:!eNULL:!LOW:!EXP:RC4+RSA:+HIGH:+MEDIUM:!SSLv2
disable_plaintext_auth: no
login_dir: /var/run/dovecot/login
login_executable(default): /usr/local/libexec/dovecot/imap-login
login_executable(imap): /usr/local/libexec/dovecot/imap-login
login_executable(pop3): /usr/local/libexec/dovecot/pop3-login
mbox_read_locks: flock
mbox_write_locks: flock
mail_executable(default): /usr/local/libexec/dovecot/imap
mail_executable(imap): /usr/local/libexec/dovecot/imap
mail_executable(pop3): /usr/local/libexec/dovecot/pop3
mail_plugins(default): quota imap_quota
mail_plugins(imap): quota imap_quota
mail_plugins(pop3): quota
mail_plugin_dir(default): /usr/local/lib/dovecot/imap
mail_plugin_dir(imap): /usr/local/lib/dovecot/imap
mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3
imap_client_workarounds(default): outlook-idle tb-extra-mailbox-sep
imap_client_workarounds(imap): outlook-idle tb-extra-mailbox-sep
imap_client_workarounds(pop3):
pop3_no_flag_updates: yes
pop3_client_workarounds(default):
pop3_client_workarounds(imap):
pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh
lda:
   auth_socket_path: /var/run/dovecot/auth-master
   postmaster_address: postmaster
   mail_plugins: quota
   sendmail_path: /usr/sbin/sendmail
auth default:
   mechanisms: plain login
   master_user_separator: *
   passdb:
     driver: passwd-file
     args: virtual.passwd
   passdb:
     driver: passwd-file
     args: username_format=%n@%l virtual.ip.passwd
   passdb:
     driver: passwd-file
     args: master.passwd
   passdb:
     driver: passwd-file
     args: master.user
     pass: yes
     master: yes
   userdb:
     driver: passwd-file
     args: virtual.passwd
   userdb:
     driver: passwd-file
     args: master.passwd
   socket:
     type: listen
     master:
       path: /var/run/dovecot/auth-master
       mode: 432
       user: vmail
       group: users