The mailing list for listmasters using Sympa

[Josemari Amatriain Martínez <address@concealed>]

Hello everybody,
We are using sympa from 10 years. All works fine until last month of August. 

A message was not sent to all subscribers of a list (lista-pdi). The list has 
1200 subscribers (taken from a source, from LDAP server) and only 800 emails 
were sent.

We are using Sympa 6.1.11 with Debian Stable, since february 2015.

We were looking for a reason in the log files. It seems that an update took 
place before the sending (as usual), but the task_manager processes updated 
the list, one second time, during the sending. At the same time, one bounce 
was received. 

I attach the log file.

Is it posible that coincidence caused an error dispatching the emails?
Some ideas with what could be wrong?

Thanks in advance.

===
 Aug 21 15:28:49 sympa1 task_manager[1887]: notice main::execute() Running 
task 
/address@concealed,
 line 0 with vars )
Aug 21 15:28:49 sympa1 task_manager[1887]: info 
List::_include_users_ldap_2level() 14 new users included from LDAP query
Aug 21 15:28:49 sympa1 task_manager[1887]: notice List::sync_include() 
List:sync_include(lista-titulados.etsia): 0 users updated
Aug 21 15:28:49 sympa1 task_manager[1887]: notice main::next_cmd() line 5 of 
sync_include : next (1440250129, INIT)
Aug 21 15:28:49 sympa1 task_manager[1887]: notice main::create() creation of 
/address@concealed
Aug 21 15:28:49 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/list_task_models/sync_include.ttl.task
Aug 21 15:28:49 sympa1 task_manager[1887]: notice main::next_cmd() --> new 
task sync_include (22 Sat Aug 2015  15 h 28 min 49 s)
Aug 21 15:38:26 sympa1 sympa[1881]: notice main::DoFile() Processing 
/address@concealed ; sender: 
=?UTF-8?Q?Vicerrectorado_de_Econom=c3=ada=2c_Planificaci=c3=b3n_y_Prof?=#012 
=?UTF-8?Q?esorado?= 
<address@concealed>#012 ; message-id: 
<address@concealed>#012
Aug 21 15:38:26 sympa1 sympa[1881]: info main::DoMessage() Processing message 
for lista-pdi with priority 5, <address@concealed>#012
Aug 21 15:38:26 sympa1 sympa[1881]: notice List::on_the_fly_sync_include() 
Synchronizing list members...
Aug 21 15:38:29 sympa1 sympa[1881]: info List::_include_users_ldap_2level() 
1206 new users included from LDAP query
Aug 21 15:38:29 sympa1 sympa[1881]: notice List::sync_include() 
List:sync_include(lista-pdi): 1 users updated
Aug 21 15:38:29 sympa1 sympa[1881]: notice List::remove_task() Removing task 
file address@concealed
Aug 21 15:38:31 sympa1 sympa[1881]: info main::DoMessage() Message for 
lista-pdi from address@concealed accepted 
(5 seconds, 242 sessions, 1207 subscribers), 
message-id=<address@concealed>#012, size=76829
Aug 21 15:38:33 sympa1 bulk[1893]: info Workload increased: 238 packets to 
process. Creating 1 child bulks to increase sending rate.
Aug 21 15:38:33 sympa1 bulk[1893]: info Starting bulk child daemon, pid 16223
Aug 21 15:38:33 sympa1 bulk[16223]: info Bulk slave daemon started with pid 
16223
Aug 21 15:38:37 sympa1 archived[1905]: notice Archiving 
address@concealed for list address@concealed
Aug 21 15:38:47 sympa1 bulk[1893]: notice Done sending message 
<address@concealed> to list address@concealed (priority 5) in 
18 seconds since scheduled expedition date.
Aug 21 15:38:50 sympa1 task_manager[1887]: notice main::create() creation of 
/address@concealed
Aug 21 15:38:50 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/list_task_models/sync_include.ttl.task
Aug 21 15:39:50 sympa1 task_manager[1887]: notice main::execute() Running 
task 
/address@concealed, 
line 0 with vars )
Aug 21 15:39:52 sympa1 task_manager[1887]: info 
List::_include_users_ldap_2level() 1206 new users included from LDAP query
Aug 21 15:39:52 sympa1 task_manager[1887]: notice List::sync_include() 
List:sync_include(lista-pdi): 1 users updated
Aug 21 15:39:52 sympa1 task_manager[1887]: notice main::next_cmd() line 5 of 
sync_include : next (1440250793, INIT)
Aug 21 15:39:52 sympa1 task_manager[1887]: notice main::create() creation of 
/address@concealed
Aug 21 15:39:52 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/list_task_models/sync_include.ttl.task
Aug 21 15:39:52 sympa1 task_manager[1887]: notice main::next_cmd() --> new 
task sync_include (22 Sat Aug 2015  15 h 39 min 53 s)
Aug 21 15:40:22 sympa1 bounced[1899]: err List::get_subscriber() Unable to 
retrieve information from database for user address@concealed
Aug 21 15:40:22 sympa1 bounced[1899]: notice 
main::update_subscriber_bounce_history() Subscriber not found in list 
lista-pdi : address@concealed
Aug 21 15:42:52 sympa1 task_manager[1887]: notice main::execute() Running 
task 
/address@concealed, 
line 0 with vars )
Aug 21 15:42:53 sympa1 task_manager[1887]: info 
List::_include_users_ldap_2level() 361 new users included from LDAP query
Aug 21 15:42:53 sympa1 task_manager[1887]: notice List::sync_include() 
List:sync_include(lista-cdu): 0 users updated
Aug 21 15:42:53 sympa1 task_manager[1887]: notice main::next_cmd() line 5 of 
sync_include : next (1440250973, INIT)
Aug 21 15:42:53 sympa1 task_manager[1887]: notice main::create() creation of 
/address@concealed
Aug 21 15:42:53 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/list_task_models/sync_include.ttl.task
Aug 21 15:42:53 sympa1 task_manager[1887]: notice main::next_cmd() --> new 
task sync_include (22 Sat Aug 2015  15 h 42 min 53 s)
Aug 21 15:48:57 sympa1 bulk[16223]: info Process 16223 didn't send any 
message since 600 seconds, exiting.
Aug 21 15:48:57 sympa1 bulk[16223]: notice bulk.pl exited normally due to 
signal
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::execute() Running 
task 
/var/spool/sympa/task/1440165064.ACTION.purge_one_time_ticket_table._global, 
line 0 with vars )
Aug 21 15:51:54 sympa1 task_manager[1887]: info 
main::purge_one_time_ticket_table() 
task_manager::purge_one_time_ticket_table()
Aug 21 15:51:54 sympa1 task_manager[1887]: info 
SympaSession::purge_old_tickets() SympaSession::purge_old_tickets(*,)
Aug 21 15:51:54 sympa1 task_manager[1887]: notice 
main::purge_one_time_ticket_table() purge_one_time_ticket_table(): 0 row 
removed in one_time_ticket_table
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::next_cmd() line 5 of 
purge_one_time_ticket_table : next (1440251514, ACTION)
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::create() creation of 
/var/spool/sympa/task/1440251514.ACTION.purge_one_time_ticket_table._global
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/global_task_models/purge_one_time_ticket_table.daily.task
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::next_cmd() --> new 
task purge_one_time_ticket_table (22 Sat Aug 2015  15 h 51 min 54 s)
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::execute() Running 
task /var/spool/sympa/task/1440165064.ACTION.purge_logs_table._global, line 0 
with vars )
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::purge_logs_table() 
purge_logs_table(): logs purged
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::next_cmd() line 5 of 
purge_logs_table : next (1440251514, ACTION)
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::create() creation of 
/var/spool/sympa/task/1440251514.ACTION.purge_logs_table._global
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::create() with model 
/usr/share/sympa/default/global_task_models/purge_logs_table.daily.task
Aug 21 15:51:54 sympa1 task_manager[1887]: notice main::next_cmd() --> new 
task purge_logs_table (22 Sat Aug 2015  15 h 51 min 54 s)
Aug 21 15:57:55 sympa1 task_manager[1887]: notice main::execute() Running 
task 
/address@concealed,
 line 0 with vars )