Hello,
I have the next problem:

All the messages arriving to our server is being queued and not delivered.

We haven't updated any software (Plesk, qmail...)

I used qmHandle to see the queues:
Messages in local queue: 4457
Messages in remote queue: 51

Maillog:

...
Jun 20 22:41:38 srv1 qmail: 1119300098.515937 new msg 4408473
Jun 20 22:41:38 srv1 qmail: 1119300098.516068 info msg 4408473: bytes 2014 from <DrWEB-DAEMON@srv1.neointeractiva.com> qp 23464 uid 2020
Jun 20 22:41:38 srv1 qmail: 1119300098.781976 starting delivery 2059: msg 4408473 to remote postmaster@srv1.neointeractiva.com
Jun 20 22:41:38 srv1 qmail: 1119300098.782096 status: local 10/10 remote 1/20
Jun 20 22:41:38 srv1 qmail: 1119300098.786388 new msg 4408474
Jun 20 22:41:38 srv1 qmail: 1119300098.786478 info msg 4408474: bytes 170713 from <levante@faxsystem.org> qp 23465 uid 2020
Jun 20 22:41:38 srv1 qmail: 1119300098.812966 delivery 2059: failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local._(#5.4.6)/
Jun 20 22:41:38 srv1 qmail: 1119300098.813286 status: local 10/10 remote 0/20
Jun 20 22:41:38 srv1 qmail-queue: dwlib[23467]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Jun 20 22:41:38 srv1 qmail-queue: dwlib[23467]: scan: the message(drweb.tmp.lJLhv1) sent by to DrWEB-DAEMON@srv1.neointeractiva.com should be passed without checks, because contains uncheckable addresses
Jun 20 22:41:38 srv1 qmail: 1119300098.869736 bounce msg 4408473 qp 23467
Jun 20 22:41:38 srv1 qmail: 1119300098.869837 end msg 4408473
Jun 20 22:41:38 srv1 qmail: 1119300098.870234 new msg 4408475
Jun 20 22:41:38 srv1 qmail: 1119300098.870323 info msg 4408475: bytes 2721 from <> qp 23468 uid 2522
Jun 20 22:41:38 srv1 qmail: 1119300098.925842 starting delivery 2060: msg 4408475 to remote DrWEB-DAEMON@srv1.neointeractiva.com
Jun 20 22:41:38 srv1 qmail: 1119300098.925889 status: local 10/10 remote 1/20
Jun 20 22:41:38 srv1 qmail: 1119300098.934217 delivery 2060: failure: Sorry._Although_I'm_listed_as_a_best-preference_MX_or_A_for_that_host,/it_isn't_in_my_control/locals_file,_so_I_don't_treat_it_as_local._(#5.4.6)/
...

Any ideas? What can I do to restore the service?

Check and make sure that srv1.neointeractiva.com is in /var/qmail/control/me file.

The messages queued are sent after a system reboot but now all incoming messages are rejected:

PERM_FAILURE: SMTP Error (state 13): 554 mail server permanently rejected message (#5.3.0)


/var/qmail/control/me file:
srv1.neointeractiva.com

At about 12:50 pm all mail to my box stop arriving. Below a snip from the log; is this perhaps the same issue?

Feb 17 15:36:46 servername qmail: 1140208606.190639 status: local 10/10 remote 4/20
Feb 17 15:36:46 servername pop3d: Connection, ip=[...]
Feb 17 15:36:46 servername qmail-queue: dwlib[16277]: mail: all addreses are uncheckable - need to skip scanning (by deny mode)
Feb 17 15:36:46 servername qmail-queue: dwlib[16277]: scan: the message(drweb.tmp.hAsxHE) sent by foo@mydomain.net to moo@foo.com should be passed without checks, because contains uncheckable addresses
Feb 17 15:36:46 servername qmail: 1140208606.545202 new msg 4881204
Feb 17 15:36:46 servername qmail: 1140208606.545354 info msg 4881204: bytes 337215 from <joe@bloe.net> qp 16288 uid 2020
Feb 17 15:36:46 servername qmail: 1140208606.561982 starting delivery 660971: msg 4881204 to remote moo@foo.com
Feb 17 15:36:46 servername qmail: 1140208606.562027 status: local 10/10 remote 5/20
Feb 17 15:36:46 servername pop3d: LOGIN, user=andrea, ip=[...]
Feb 17 15:36:46 servername qmail: 1140208606.821025 delivery 660965: deferral: Sorry,_I_wasn't_able_to_establish_an_SMTP_connection._(#4.4.1)/

(IP's & emails obfuscated)

I have a client who tries to send email from her domain to another domain and that domain cannot receive any of her emails as they get stuck in mail queue and don't deliver but her emails to all other domains deliver just fine.