New install (v5.4.5-3) mail

[twistedpixel]

Describe the bug
I just installed v5.4.5-3 of MailScanner on my Ubuntu server (running Plex, using postfix) and configured exactly as described on https://mailscanner.info/postfix

On adding the milter (inet:127.0.0.1:33333) to postfix's main.cf, no mail is delivered to user inbox. Logs suggest "DISCARD" was triggered and also have entries "Unable to kick message" and "Unable to open QMQP socket at 127.0.0.1 on port 628"

I checked the permissions for /var/spool/MailScanner/milterin and /var/spool/MailScanner/milterout and they are as expected: postfix:postfix

To Reproduce
Steps to reproduce the behavior:
Install MailScanner, configure as per installation/config guide, send email to/from domain hosted on server

Expected behavior
Mail passed through MailScanner and delivered to inbox

Examples

-- Below are the logs for a particular message I tested but also seen in logs is "Unable to open QMQP socket at 127.0.0.1 on port 628" repeatedly

2023-06-19 16:15:27	postfix/smtpd	client=unknown[[REDACTED]], sasl_method=DIGEST-MD5, sasl_username=[REDACTED]
2023-06-19 16:15:27	psa-pc-remote	from=<[REDACTED]> to=<[REDACTED]>
2023-06-19 16:15:27	postfix/cleanup	message-id=<F17B9E17-93C0-4FD9-A7B4-BA18E3840F91@[REDACTED]>
2023-06-19 16:15:28	amavis	(3330191-04) Passed CLEAN {AcceptedInternal}, AM.PDP-SOCK/SUBMISSION LOCAL [149.34.246.34] [149.34.246.34] <[REDACTED]> -> <[REDACTED]>, Queue-ID: 53398A0098, Message-ID: <F17B9E17-93C0-4FD9-A7B4-BA18E3840F91@[REDACTED]>, mail_id: ixeglJYfA_TJ, Hits: -1.162, size: 2458, 721 ms
2023-06-19 16:15:28	psa-pc-remote	py-limit-out: stderr: INFO:main:Setting 'X-PPP-Vhost' header to '[REDACTED]'
2023-06-19 16:15:28	psa-pc-remote	py-limit-out: stderr: PASS
2023-06-19 16:15:28	psa-pc-remote	check-quota: stderr: SKIP
2023-06-19 16:15:28	psa-pc-remote	spf: stderr: PASS
2023-06-19 16:15:28	psa-pc-remote	dk_sign: stderr: PASS
2023-06-19 16:15:28	postfix/cleanup	milter-discard: END-OF-MESSAGE from unknown[[REDACTED]]: milter triggers DISCARD action; from=<[REDACTED]> to=<[REDACTED]> proto=ESMTP helo=<smtpclient.apple>
2023-06-19 16:15:32	MailScanner	Requeue: 53398A0098.A44EA to 53398A0098.A44EA
2023-06-19 16:15:32	MailScanner	Unable to kick message /var/spool/MailScanner/milterout/53398A0098.A44EA, will retry soon...
2023-06-19 16:15:45	MailScanner	Unable to kick message /var/spool/MailScanner/milterout/53398A0098.A44EA, will retry soon...

Server (please complete the following information):

• OS: [Ubuntu]
• Mandatory Access Control Enforcement: [none]
• MailScanner Version: [5.4.5-3 ]
• OS Version: [20.04.6 LTS ]
• Installation method: [ package from Github ]
• Installation: [ New ]
• Containerized: [ If you mean like Docker, no ]

Additional context

[github-actions]

Thank you for submitting your first issue to MailScanner! We will respond to you soon!

[utpaldesai]

If MTA and mailscanner are installed on same box, it worked for me

1. edit MailScanner.conf
   go to line milter ignore loopback = yes change to no
2. edit master.cf
   go to line Fix conditional for strings #628 inet n - - - - qmqpd
   remove #

[shawniverson]

Making sure qmqpd is available and configured properly in master.conf is the solution.