==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.0 MARIADB edition.
- Deployed with iRedMail Easy or the downloadable installer? downloadable
- Linux/BSD distribution name and version: CentOS Linux release 7.7.1908 (Core)
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx):Nginx
- Manage mail accounts with iRedAdmin-Pro? iRedAdmin
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
/var/log/maillog

Aug 26 08:10:48 mail roundcube: PHP Warning:  stream_socket_client(): unable to connect to 127.0.0.1:587 (Connection refused) in /opt/www/roundcubemail-1.4.1/vendor/pear/net_socket/Net/Socket.php on line 159
Aug 26 08:10:48 mail roundcube: <ccckcipt> PHP Error: Connection refused (POST /mail/?_task=mail&_unlock=loading1598429449187&_framed=1&_lang=en_US&_action=send)
Aug 26 08:10:48 mail roundcube: <ccckcipt> PHP Error: Failed to connect socket: Connection refused (POST /mail/?_task=mail&_unlock=loading1598429449187&_framed=1&_lang=en_US&_action=send)
Aug 26 08:10:48 mail roundcube: <ccckcipt> SMTP Error: Connection failed: Failed to connect socket: Connection refused in /opt/www/roundcubemail-1.4.1/program/lib/Roundcube/rcube.php on line 1689 (POST /mail/?_task=mail&_unlock=loading1598429449187&_framed=1&_lang=en_US&_action=send)

netstat -tlpn | grep 587
return null
点击发送以后会报下边截图的错，同时日志打印如上。587这个端口没有监听，但是检查iredapd、postfix都是正常。原来收发邮件都可以，后边不知道什么原因现在收发邮件都不通了。麻烦看下，谢谢。