Hi I have iredmail 0.9.1 working on Centos 7, but suddenly stops sending mails, i tried with ubuntu 15, with postgre db,with mariadb wirth de same result, reboting server it resolves. I appreciate your help.

==== Required information ====
- iRedMail version:  0.9.1
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MAriaDB
- Web server (Apache or Nginx):  Apache
- Linux/BSD distribution name and version: CENTOS 7

mail.log shows this:

mail postfix/smtpd[13267]: disconnect from unknown[170.0.4.251]
May 28 15:21:53 mail postfix/smtpd[13501]: connect from mail.boliviavirtualmarket.info[199.89.54.114]
May 28 15:21:55 mail postfix/smtpd[13501]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:21:55 mail postfix/smtpd[13501]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:21:55 mail postfix/smtpd[13501]: NOQUEUE: reject: RCPT from mail.boliviavirtualmarket.info[199.89.54.114]: 451 4.3.5 Server configuration problem; from=<rebotes@sugierelo.com> to=<pablo.rojas@efarma.com.bo> proto=ESMTP helo=<mail.boliviavirtualmarket.info>
May 28 15:21:56 mail postfix/smtpd[13501]: disconnect from mail.boliviavirtualmarket.info[199.89.54.114]
May 28 15:24:31 mail postfix/anvil[12008]: statistics: max connection rate 1/60s for (submission:170.0.4.42) at May 28 15:17:11
May 28 15:24:31 mail postfix/anvil[12008]: statistics: max connection count 1 for (submission:170.0.4.42) at May 28 15:17:11
May 28 15:24:31 mail postfix/anvil[12008]: statistics: max cache size 1 at May 28 15:17:11
May 28 15:25:48 mail postfix/smtpd[13586]: connect from mail.saebolivia.com[190.129.69.163]
May 28 15:25:49 mail postfix/smtpd[13586]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:25:49 mail postfix/smtpd[13586]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:25:50 mail postfix/smtpd[13586]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:25:50 mail postfix/smtpd[13586]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:25:50 mail postfix/smtpd[13586]: NOQUEUE: reject: RCPT from mail.saebolivia.com[190.129.69.163]: 451 4.3.5 Server configuration problem; from=<mnieva@saebolivia.com> to=<patricia.pacheco@efarma.com.bo> proto=ESMTP helo=<mail.saebolivia.com>
May 28 15:25:54 mail postfix/smtpd[13586]: disconnect from mail.saebolivia.com[190.129.69.163]
May 28 15:26:10 mail postfix/smtpd[13594]: connect from scz-190-104-20-00146.wimaxtigo.bo[190.104.20.146]
May 28 15:27:10 mail postfix/smtpd[13611]: warning: hostname ip-adsl-190.180.31.69.cotas.com.bo does not resolve to address 190.180.31.69
May 28 15:27:10 mail postfix/smtpd[13611]: connect from unknown[190.180.31.69]
May 28 15:27:12 mail postfix/smtpd[13611]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:27:12 mail postfix/smtpd[13611]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:27:13 mail postfix/smtpd[13611]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:27:13 mail postfix/smtpd[13611]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:27:13 mail postfix/smtpd[13611]: NOQUEUE: reject: RCPT from unknown[190.180.31.69]: 451 4.3.5 Server configuration problem; from=<mariela.moreno@efarma.com.bo> to=<stratos_pat@hotmail.com> proto=ESMTP helo=<MMORENO>
May 28 15:27:24 mail postfix/smtpd[13611]: disconnect from unknown[190.180.31.69]
May 28 15:29:11 mail postfix/smtpd[13637]: connect from mail5.megapharma.com[200.124.194.195]
May 28 15:29:12 mail postfix/smtpd[13637]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:29:12 mail postfix/smtpd[13637]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:29:13 mail postfix/smtpd[13637]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:29:13 mail postfix/smtpd[13637]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:29:13 mail postfix/smtpd[13637]: NOQUEUE: reject: RCPT from mail5.megapharma.com[200.124.194.195]: 451 4.3.5 Server configuration problem; from=<mdiaz@bo.roemmers.com> to=<patricia.pacheco@efarma.com.bo> proto=ESMTP helo=<mail5.megapharma.com>
May 28 15:29:14 mail postfix/smtpd[13637]: disconnect from mail5.megapharma.com[200.124.194.195]
May 28 15:29:52 mail postfix/smtpd[13652]: warning: hostname ip-adsl-190.180.31.69.cotas.com.bo does not resolve to address 190.180.31.69
May 28 15:29:52 mail postfix/smtpd[13652]: connect from unknown[190.180.31.69]
May 28 15:29:57 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:29:57 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:29:58 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:29:58 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:29:58 mail postfix/smtpd[13652]: NOQUEUE: reject: RCPT from unknown[190.180.31.69]: 451 4.3.5 Server configuration problem; from=<mariela.moreno@efarma.com.bo> to=<lindauraus.pust@gmail.com> proto=ESMTP helo=<MMORENO>
May 28 15:29:59 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:29:59 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:30:00 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:30:00 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:30:00 mail postfix/smtpd[13652]: NOQUEUE: reject: RCPT from unknown[190.180.31.69]: 451 4.3.5 Server configuration problem; from=<mariela.moreno@efarma.com.bo> to=<r.cossio@displasproducciones.com> proto=ESMTP helo=<MMORENO>
May 28 15:30:00 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:30:00 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:30:01 mail postfix/smtpd[13652]: warning: connect to 127.0.0.1:7777: Connection refused
May 28 15:30:01 mail postfix/smtpd[13652]: warning: problem talking to server 127.0.0.1:7777: Connection refused
May 28 15:30:01 mail postfix/smtpd[13652]: NOQUEUE: reject: RCPT from unknown[190.180.31.69]: 451 4.3.5 Server configuration problem; from=<mariela.moreno@efarma.com.bo> to=<rosembergzs@yahoo.es> proto=ESMTP helo=<MMORENO>
May 28 15:30:05 mail postfix/smtpd[13637]: connect from o11.s6.fastgb.com[50.97.113.236]
- Related log if you're reporting an issue:
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