* clamav: set `MaxConnectionQueueLength` to its default value (200), custom (15) was way too small and caused recurrent connections fail in Postfix.

* postfix (packmail only): disable `concurrency_failed_cohort_limit` for destination smtp-amavis to prevent the suspension of this destination when Amavis fails to answer. Indeed, we configure the suspension delay quite long in `minimal_backoff_time` (2h) and `maximal_backoff_time` (6h) to reduce the risk of ban from external SMTPs.

CHANGELOG.md

@@ -30,6 +30,8 @@ The **patch** part changes is incremented if multiple releases happen the same m
 * docker-host: fix type in daemon.json and remove host configuration that is already in the systemd service by default
 * haproxy: fix missing admin ACL in stats module access permissions
 * openvpn: fix the client cipher configuration to match the server cipher configuration
+* clamav: set `MaxConnectionQueueLength` to its default value (200), custom (15) was way too small and caused recurrent connections fail in Postfix.
+* postfix (packmail only): disable `concurrency_failed_cohort_limit` for destination smtp-amavis to prevent the suspension of this destination when Amavis fails to answer. Indeed, we configure the suspension delay quite long in `minimal_backoff_time` (2h) and `maximal_backoff_time` (6h) to reduce the risk of ban from external SMTPs.
 
 ### Removed
 

clamav/tasks/main.yml

@@ -13,7 +13,7 @@
     - { key: 'clamav-daemon/StreamMaxLength', type: 'string', value: '25' }
     - { key: 'clamav-daemon/ReadTimeout', type: 'string', value: '180' }
     - { key: 'clamav-daemon/StatsEnabled', type: 'boolean', value: 'false' }
-    - { key: 'clamav-daemon/MaxConnectionQueueLength', type: 'string', value: '15' }
+    - { key: 'clamav-daemon/MaxConnectionQueueLength', type: 'string', value: '200' }
     - { key: 'clamav-daemon/LogRotate', type: 'boolean', value: 'true' }
     - { key: 'clamav-daemon/AllowAllMatchScan', type: 'boolean', value: 'true' }
     - { key: 'clamav-daemon/ScanOnAccess', type: 'boolean', value: 'false' }

postfix/templates/packmail_main.cf.j2

@@ -412,6 +412,7 @@ smtpd_sasl_path = private/auth-client
 
 # Amavis and OpenDKIM
 content_filter = smtp-amavis:[127.0.0.1]:10024
+smtp-amavis_destination_concurrency_failed_cohort_limit = 0
 smtpd_milters = inet:[127.0.0.1]:8891
 non_smtpd_milters = inet:[127.0.0.1]:8891