========- iRedMail version (check /etc/iredmail-release): 0.9.2
- Linux/BSD distribution name and version: Centos 7 minimal install
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MYSQL
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro?no
- Related log if you're reporting an issue:
====
Firewall shows open, server is listening, but testing from another device: Operation timed out.
main.cf and master.cf attached

rdm-imac:~ rdm$ nc -v srv.ryanmilton.xyz 587
nc: connectx to srv.ryanmilton.xyz port 587 (tcp) failed: Operation timed out

[root@srv rmilton]# netstat -ntulp | grep 587
tcp        0      0 0.0.0.0:587             0.0.0.0:*               LISTEN      4179/master
[root@srv rmilton]# firewall-cmd --list-all
iredmail (default, active)
  interfaces: eno1
  sources:
  services: http https imap imaps plexmediaserver pop3 pop3s smtp ssh submission
  ports: 443/tcp 587/tcp 993/tcp
  masquerade: no

/etc/firewalld/services shows the following for submission.xml:

tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      3264/nginx: master
<?xml version="1.0" encoding="utf-8"?>
<service>
  <short>SMTP over TLS</short>
  <description>This option allows incoming SMTP mail delivery over TLS.</description>
  <port protocol="tcp" port="587"/>
</service>