==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
-IRedAPD 3.5
- iRedAPD only
- CentOS 7
- local users
- N/A
- Just using iRedApd
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

OS CentOS 7 latest
Postfix 2.10.1
iRedAPD Version 3.5

Every time a message is sent or received this entry is logged:

Mar 16 10:34:41 mail journal: iredapd Unexpected error: 'NoneType' object has no attribute 'connect'. Fallback to default action: DUNNO

smtp_sessions in MySQL is being populated, example of outgoing smtp session:

Here is an outgoing smtp_sessions row:

                 id: 25
               time: 2020-03-16 14:22:39
           time_num: 1584368559
             action: DUNNO
             reason:
           instance: 6f0d.5e6f8baf.34902.0
     client_address: <<clientIP redacted>>
        client_name: unknown
reverse_client_name: unknown
          helo_name: <<helo_name redacted>>
             sender: <<sender email redacted>>
      sender_domain: <<sender domain redacted>>
      sasl_username: <<SASL username redacted>>
        sasl_domain: <<SASL domain redacted>>
          recipient: <<recipient redacted>>
   recipient_domain: gmail.com
encryption_protocol:
  encryption_cipher:
     server_address:
        server_port:

throttle_tracking in MySQL is not being populated

Here is the throttle setting:

MariaDB [iredapd]> select * from throttle;
+----+---------+----------+----------+--------+----------+----------+-----------+
| id | account | kind     | priority | period | msg_size | max_msgs | max_quota |
+----+---------+----------+----------+--------+----------+----------+-----------+
|  1 | @.      | outbound |        0 |     60 |        0 |      100 |         0 |
+----+---------+----------+----------+--------+----------+----------+-----------+

Relevant postfix configuration:

smtpd_recipient_restrictions =
        check_policy_service inet:127.0.0.1:7777,
        ...
        reject
smtpd_end_of_data_restrictions = check_policy_service inet:127.0.0.1:7777

iRedApd config:

# Listen address and port.
listen_address = '127.0.0.1'
# Port for normal Postfix policy requests.
listen_port = 7777
# Ports for SRS (Sender Rewriting Scheme).
# - `srs_forward_port` is used in Postfix parameter `sender_canonical_maps`.
# - `recipient_canonical_maps` is used in Postfix parameter `recipient_canonical_maps`.
#srs_forward_port = 7778
#srs_reverse_port = 7779
# SRS (Sender Rewriting Scheme)
#
# The secret key(s) used to generate cryptographic hash.
# The first secret key is used for generating AND verifying hash in SRS
# address. If you have old keys, you can append them also for verification only.
srs_secrets = []

# Rewrite address will be 'xxx@<srs_domain>', so please make sure `srs_domain`
# is a resolvable mail domain name and pointed to your server.
srs_domain = ''
# Run as a low privileged user.
run_as_user = 'iredapd'
# Path to pid file.
pid_file = '/var/run/iredapd.pid'
# Log level: info, debug.
log_level = 'debug'
# Backend: ldap, mysql, pgsql.
backend = 'mysql'
# Enabled plugins.
plugins = ['throttle']

# iRedAPD database, used for greylisting, throttle.
iredapd_db_server = '127.0.0.1'
iredapd_db_port = '3306'
iredapd_db_name = 'iredapd'
iredapd_db_user = 'iredapd'
iredapd_db_password = '<<redacted>>'