Why do emails come and go only when the server is restarted?

Question

Mail server

Hello.
Hmailserver stopped receiving and sending mail. I send from external to a corporate party: either it doesn’t arrive, or it arrives with a delay of a couple of hours. Inside the domain is the same story. From one to another leaves, but is not visible in the inbox. As soon as I restart the machine on which hmail is installed, the recipients immediately receive mail. As soon as it enters the system, everything is again neither here nor there. And everything is sent without any errors. Help folks.
Here are the diagnostic logs:
Test: Collect server details
hMailServer version: hMailServer 5.6-B2145
Database type: MySQL
Test: Test IPv6
IPv6 support is available in operating system.
Test: Test outbound port
SMTP relayer not in use. Attempting mail.hmailserver.com:25...
Trying to connect to host mail.hmailserver.com...
Trying to connect to TCP/IP address 46.163.109.39 on port 25.
Received: 220 mail.hmailserver.com ESMTP.
Connected successfully.
Test: Test backup directory
ERROR: Backup directory has not been specified.
Test: Test MX records
Trying to resolve MX records for energonazorat.uz...
Host name found: mail.energonazorat.uz
Test: Test local connect
Connecting to TCP/IP address in MX records for local domain domain energonazorat.uz...
Trying to connect to host mail.energonazorat.uz... Trying to connect to TCP
/IP address fe80::6d53:d377:c786:7096%12 on port 25.
25.
Received: 220 mail.energonazorat.uz ESMTP.
Connected successfully.
Test: Test message file locations
Relative message paths are stored in the database for all messages.
Test: Test IP range configuration
No problems were found in the IP range configuration.

Answer 1

Have you looked at the mail queue?