==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version:  Ubuntu 14.0 lts
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): ldap
- Web server (Apache or Nginx): apache- Manage mail accounts with iRedAdmin-Pro?
- Related log if you're reporting an issue:
====
In my setup, I installed on my server iRedMail post without amavis. Amavis the services installed on another server, however, to receive an email receipt errors of server connectivity amavis.

Mail.log (Servidor amavis):
Dec 17 15:04:40 viper3 amavis[22757]: (22757-03) (!)connect to [viper1.lab.tepuy.top]:10025 failed, attempt #1: Can't connect to INET6 socket [viper1.lab.tepuy.top]:10025: Connection refused
Dec 17 15:04:40 viper3 amavis[22757]: (22757-03) (!)FWD from <root@viper2.lab.tepuy.top> -> <dgarcia@viper1.lab.tepuy.top>, 451 4.5.0 From MTA() during fwd-connect (All attempts (1) failed connecting to smtp:[viper1.lab.tepuy.top]:10025): id=22757-03
Dec 17 15:04:40 viper3 amavis[22757]: (22757-03) Blocked MTA-BLOCKED {TempFailedInbound}, <root@viper2.lab.tepuy.top> -> <dgarcia@viper1.lab.tepuy.top>, Message-ID: <20151217150446.0838262138@viper2.lab.tepuy.top>, mail_id: dXnDwCPx9KNw, Hits: 0, size: 359, 1469 ms

Mail.log (Servidor de correos):
Dec 17 15:04:46 viper2 postfix/pickup[22029]: 0838262138: uid=0 from=<root@viper2.lab.tepuy.top>
Dec 17 15:04:46 viper2 postfix/cleanup[22202]: 0838262138: message-id=<20151217150446.0838262138@viper2.lab.tepuy.top>
Dec 17 15:04:46 viper2 postfix/qmgr[22030]: 0838262138: from=<root@viper2.lab.tepuy.top>, size=359, nrcpt=1 (queue active)
Dec 17 15:04:47 viper2 postfix/smtp[22205]: 0838262138: to=<dgarcia@viper1.lab.tepuy.top>, relay=10.181.203.115[10.181.203.115]:10024, delay=1.6, delays=0.08/0.04/0/1.5, dsn=4.5.0, status=deferred (host 10.181.203.115[10.181.203.115] said: 451 4.5.0 id=22757-03 - Temporary MTA failure on relaying, From MTA() during fwd-connect (All attempts (1) failed connecting to smtp:[viper1.lab.tepuy.top]:10025): id=22757-03 (in reply to end of DATA command))

I appreciate the cooperation that may lend.