==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.3.2 (MARIADB edition)
- Deployed with iRedMail Easy or the downloadable installer? Downloadable installer
- Linux/BSD distribution name and version: CentOS-7-x64-minimal +headless
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MariaDB
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? No
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
OS: CentOS-7-x64-minimal +headless

Hiya,

I installed the iRedMail and it was successful as I didn't get any error during installation. I do still have an issue with My Domain pointing to Server and my Server pointing to my domain as I described here and seek help, please https://forum.iredmail.org/post79068.html#p79068  ?

But aside from that, as I do install the iRedMail without error, I shall be able to access these by my IP(I installed the RoundCube and iRedMail and I shall have access to below):
Roundcube webmail: httpS://{my Server IP}/mail/
Web admin panel (iRedAdmin): httpS://{my Server IP}/iredadmin/

or

Roundcube webmail: http://{my Server IP}/mail/
Web admin panel (iRedAdmin): http://{my Server IP}/iredadmin/

Are the iRedMail installs the SSL(LetsEncryptSSL) by default or I shall install it manually and configure it manually myself, please help?

I reinstalled iRedMail with the fresh configuration on the same folder that I initially installed the iRedMail and below is the service status again:
https://ibb.co/zs8kS4f

I checked the iredmail service status as below(Active and Loaded):
https://ibb.co/0rHRscJ

Roundcube webmail: httpS://{my Server IP}/mail/
https://ibb.co/J7tKLyM
{sometimes it gave Bad Gateway error in red in Roundcube, I believe it may be the firewall, When I took this screenshot. I disabled the firewall. I use CSF firewall.}

Web admin panel (iRedAdmin): httpS://{my Server IP}/iredadmin/
https://ibb.co/qrCmYzj
{Now after reinstall Started working}

I created a test email named aaa@{my domain}.com and sent four emails to different mail accounts on mine on different servers. I didn't receive ANY of the emails, nor I can receive any email on my email address(I believe this is related to my domain setup issue here  https://forum.iredmail.org/post79068.html#p79068 ). May please help me troubleshoot and I will send a screenshot of the commands you mention here to help you identify my problem, please?

I want to troubleshoot everything and every service to be sure all are up and running. May someone help me do this by providing instructions, please? I want names of ALL services that shall be running to check to be sure they are not stopped, please? I will post the output on every instruction on the screenshot back here?

Currently, I'm not able to send or receive any email. For testing purposes, I turned the CSF firewall off and also I checked that port 25 is open by telnet as https://ibb.co/nBP5rv0  When I sent emails or waited to receive emails, the CSF firewall was off, and Fail2ban was disabled. I checked and I'm sure 'firewalld' was disabled and masked, thus it wasn't active either. This is a CentOS-7-x64-minimal(+headless) and nothing installed specifically installed on this server. May please help me fix this issue, please help me troubleshoot?

As I use CSF+LFD, I disabled the Fail2Ban,
https://ibb.co/927ZW6M

There are many logs here, I don't know where shall I start to check specifically the logs on '/var/log/maillog' are long lines of logs:
https://ibb.co/1Thm17Z

Before installation I have done the blew configurations, are they correct:
------------------------start-------------------------
>vi /etc/hostname
mail.{myDomain}.com

>vi /etc/hosts
{It was as below:}
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain104

{I changed it to this:}
{my Server IP} mail.{my Domain}.com
127.0.0.1 mail.{my Domain}.com mail localhost localhost.localdomain

>vi /etc/hosts
{my Server IP} mail.{my Domain}.com
127.0.0.1 mail.{my Domain}.com mail localhost localhost.localdomain
------------------------End-----------------------------------

The ports mentioned here do not give any information if they are TCP or UDP and whether I shall leave the incoming or outgoing on the CSF-Firewall open, could you please elaborate as I need to keep the minimum possible ports open and I'm the only one who uses this email service, thus I need customized advice on how to harden the security on the ports and everything and leave the limited ports open, and if it's not required to leave ports open two-sided, I want to keep the minimum possible pots sides open? e.g. do I need to leave 443, 80, etc open two-sided open on TCP or just one-sided, for incoming on TCP only? May please advise on all the ports list?
I prefer to allow minimum required ports to pass the CSF+LFD firewall, could you elaborate a list of incoming TCP/ incoming UDP and outgoing TCP/ outgoing UDP ports that I shall allow in my CSF_LFD firewall to let the iRedMail work even when the CSF+LFD firewall is on? (when I tested I turned off the firewall as I mentioned, thus the mail send/receive issue was not in the firewall.)

Please help?

Tnx and best of luck