==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):  1.7.4 MARIADB edition.
- Deployed with iRedMail Easy or the downloadable installer? downloadable installer
- Linux/BSD distribution name and version: AlmaLinux release 10.1 (Heliotrope Lion)
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I migrated some domains from one server with iRedMail to another and kept the same configurations for dovecot, postfix, amavisd, and iredapd. However, some accounts on the new server are accumulating messages in the email queue:

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Received: by mail001.xpto.com.br (Postfix)
    id 4g90vf4sR6z4y0P; Tue,  5 May 2026 11:17:18 -0300 (-03)
Date: Tue,  5 May 2026 11:17:18 -0300 (-03)
From: Mail Delivery System <MAILER-DAEMON@mail001.xpto.com.br>
To: Postmaster <postmaster@mail001.xpto.com.br>
Subject: Postfix SMTP server: errors from 195-154-118-127.rev.poneytelecom.eu[195.154.118.127]:43730
Message-Id: <4g90vf4sR6z4y0P@mail001.xpto.com.br>

Transcript of session follows.

Out: 220 mail001.xpto.com.br ESMTP Postfix
In:  EHLO sd-141991.dedibox.fr
Out: 250-mail001.xpto.com.br
Out: 250-PIPELINING
Out: 250-SIZE 31457280
Out: 250-ETRN
Out: 250-STARTTLS
Out: 250-ENHANCEDSTATUSCODES
Out: 250-8BITMIME
Out: 250 DSN
In:  STARTTLS
Out: 220 2.0.0 Ready to start TLS
In:  EHLO sd-141991.dedibox.fr
Out: 250-mail001.xpto.com.br
Out: 250-PIPELINING
Out: 250-SIZE 31457280
Out: 250-ETRN
Out: 250-ENHANCEDSTATUSCODES
Out: 250-8BITMIME
Out: 250 DSN
In:  MAIL From:<www-data@sd-141991.dedibox.fr> SIZE=677580 BODY=8BITMIME
Out: 250 2.1.0 Ok
In:  RCPT To:<financeiro@dominio.com.br>
Out: 451 4.3.5 Server configuration error
In:  DATA
Out: 554 5.5.1 Error: no valid recipients
In:  RSET
Out: 250 2.0.0 Ok
Out: 421 4.4.2 mail001.xpto.com.br Error: timeout exceeded

Session aborted, reason: timeout

For other details, see the local mail logfile
---

All services are working correctly (mariadb, dovecot, postfix, iredapd, etc.). The postfix logs show this message:

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postfix/smtp.log:May  5 14:06:12 mail001 postfix/smtpd[1361542]: NOQUEUE: reject: RCPT from 195-154-118-127.rev.poneytelecom.eu[195.154.118.127]:40826: 451 4.3.5 Server configuration error; from=<www-data@sd-141991.dedibox.fr> to=<financeiro@dominio.com.br> proto=ESMTP helo=<sd-141991.dedibox.fr>
---

The iredapd logs show this message:

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iredapd/iredapd.log: May  5 12:57:59 mail001 python3[1271302]: iredapd [216.245.218.125] RCPT, uwnpw7lo@interestingthing.online -> financeiro@dominio.com.br, 451 4.7.1 Intentional policy rejection, please try again later [sasl_username=, sender=uwnpw7lo@interestingthing.online, client_name=special.interestingthing.online, reverse_client_name=special.interestingthing.online, helo=special.interestingthing.online, encryption_protocol=, encryption_cipher=, server_port=25, process_time=0.4227s]
---

Any guidance about this issue?