dovecot - Aug 2012 - antispam_plugin prevents IMAP login (error 3) [Dovecot 2.0.19]

Hi everybody,

trying to get the Dovecot antispam_plugin to work and I must be doing 
something wrong, because as soon as it is enabled with a certain 
backend, imap logins do not work anymore (the session is immediately 
closed after a successful login). Interestingly, pipe and spool2dir are 
working (that is, the session won't be closed), dspam-exec and 
crm114-exec are not. If this happens, mail_debug output is as follows:

   imap-login: Login: user=<dof>, method=PLAIN, rip=127.0.0.1, 
lip=127.0.0.1, mpid=10420, secured
   imap: Debug: Loading modules from directory: /usr/lib/dovecot/modules
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib20_autocreate_plugin.so
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib20_fts_plugin.so
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib21_fts_squat_plugin.so
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib90_antispam_plugin.so
   imap(dof): Debug: Effective uid=23244, gid=8, 
home=/var/spool/dovecot/userdata/dof
   imap(dof): Debug: Home dir not found: /var/spool/dovecot/userdata/dof
   master: Error: service(imap): child 10420 returned error 3

Without the plugin I get:

   imap-login: Login: user=<dof>, method=PLAIN, rip=127.0.0.1, 
lip=127.0.0.1, mpid=10469, secured
   imap: Debug: Loading modules from directory: /usr/lib/dovecot/modules
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib20_autocreate_plugin.so
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib20_fts_plugin.so
   imap: Debug: Module loaded: 
/usr/lib/dovecot/modules/lib21_fts_squat_plugin.so
   imap(dof): Debug: Effective uid=23244, gid=8, 
home=/var/spool/dovecot/userdata/dof
   imap(dof): Debug: Home dir not found: /var/spool/dovecot/userdata/dof
   imap(dof): Debug: fs: root=/var/spool/dovecot/mail/dof, index=, 
control=, inbox=/var/spool/dovecot/mail/dof/INBOX, alt   imap(dof): Debug:
Namespace : Using permissions from
/var/spool/dovecot/mail/dof: mode=0755 gid=-1


Hopefully this is just a configuration problem. I tried the plugin in 
the Ubuntu repository (I'm using LTS 12.04) and even checked out the 
source from git and compiled it myself, but to no avail.


Thanks a lot in advance and best regards,
Florian


-------------------

dovecot -n output:

auth_cache_size = 128 k
auth_cache_ttl = 20 mins
auth_failure_delay = 10 secs
auth_mechanisms = plain login
disable_plaintext_auth = no
login_greeting = Projektfabrik IMAP ready.
mail_gid = mail
mail_home = /var/spool/dovecot/userdata/%u
mail_location = 
maildir:/var/spool/dovecot/mail/%u:INBOX=/var/spool/dovecot/mail/%u/INBOX:LAYOUT=fs
mail_uid = dovemail
managesieve_notify_capability = mailto
managesieve_sieve_capability = fileinto reject envelope 
encoded-character vacation subaddress comparator-i;ascii-numeric 
relational regex imap4flags copy include variables body enotify 
environment mailbox date
passdb {
   args = /etc/dovecot/dovecot-ldap.conf
   driver = ldap
}
plugin {
   antispam_backend = dspam-exec
   antispam_dspam_binary = /usr/bin/dspam
   antispam_signature = X-DSPAM-Signature
   antispam_signature_missing = error
   antispam_spam = Spam
   antispam_trash = trash;Trash;Deleted Items; Deleted Messages
   autocreate = INBOX/Sent Mail
   autocreate2 = INBOX/Spam
   autocreate3 = INBOX/Trash
   autosubscribe = INBOX/Sent Mail
   autosubscribe2 = INBOX/Spam
   autosubscribe3 = INBOX/Trash
   fts = squat
   sieve = /var/spool/dovecot/sieve/%u/defaultbc
   sieve_before = /etc/dovecot/sieve/spam.sieve
   sieve_dir = /var/spool/dovecot/sieve/%u
}
protocols = imap pop3 sieve
service auth {
   unix_listener /var/spool/postfix/private/dovecot-auth {
     group = postfix
     mode = 0600
     user = postfix
   }
   unix_listener auth-userdb {
     mode = 0600
     user = dovemail
   }
   user = dovenull
}
service imap-login {
   inet_listener imap {
     address = localhost
     port = 143
   }
   inet_listener imaps {
     address = localhost XX.XXX.XX.XXX
     port = 993
   }
   service_count = 1
   user = dovenull
}
service managesieve-login {
   inet_listener sieve {
     address = localhost
     port = 2000
   }
   service_count = 1
   user = dovenull
}
service pop3-login {
   inet_listener pop3 {
     address = localhost
     port = 110
   }
   inet_listener pop3s {
     address = XX.XXX.XX.XXX
     port = 995
   }
   service_count = 1
   user = dovenull
}
ssl_ca = </etc/ssl/dovecot/cacert.pem
ssl_cert = </etc/ssl/dovecot/cert.pem
ssl_key = </etc/ssl/dovecot/key.pem
protocol imap {
   imap_client_workarounds = tb-extra-mailbox-sep
   mail_plugins = antispam autocreate fts fts_squat
}
protocol pop3 {
   pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
   pop3_lock_session = yes
}
protocol lda {
   mail_fsync = optimized
   mail_plugins = sieve
   postmaster_address = postmaster at projektfabrik.com
}

> On 17.08.2012 12:06, dof at projektfabrik.com wrote:
>> Hi everybody,
>>
>> trying to get the Dovecot antispam_plugin to work and I must be doing
>> something wrong, because as soon as it is enabled with a certain
>> backend, imap logins do not work anymore (the session is immediately
>> closed after a successful login). Interestingly, pipe and spool2dir
>> are working (that is, the session won't be closed), dspam-exec and
>> crm114-exec are not. If this happens, mail_debug output is as 
>> follows:
>>
>> [...]
> 
> Hi again,
> 
> how embarrassing. I should use the correct name for the backend type. 
> :\ So everything works as expected, sorry for spamming the mailing list.
> 
> 
> Best regards,
> Florian
Florian,

I am having a very similar (or the same) issue. Ubuntu 12.04.1 LTS with
Dovecot 2.0.19.

Do you mind sharing the details of your configuration, and what,
exactly, you changed with respect to the back-end to resolve the issue?

a.) Which back-end are you using?

b.) What are your "plugin {}" configuration directives?

I'm attempting to use mailtrain, per
http://wiki2.dovecot.org/Plugins/Antispam .

My configuration directives are:

plugin {
  antispam_backend = mailtrain
  antispam_mail_sendmail = /usr/bin/sa-learn-pipe.sh
  antispam_mail_spam = --spam
  antispam_mail_notspam = --ham
  antispam_spam_pattern_ignorecase = spam;junk
}

Thanks for any help!

-Ben