From 05d5617c291f07cb3e969bde2f7d7621a8d5c33b Mon Sep 17 00:00:00 2001
From: ale <ale@incal.net>
Date: Mon, 30 Dec 2024 09:13:34 +0000
Subject: [PATCH] Enable VERP for (some) outbound emails

Improve bounce detection.

Also reduce the number of recipients per single SMTP delivery.
---
 roles/mailman/templates/mm_cfg.py.j2 | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/roles/mailman/templates/mm_cfg.py.j2 b/roles/mailman/templates/mm_cfg.py.j2
index 3fdbb8b8..b0cd8f89 100644
--- a/roles/mailman/templates/mm_cfg.py.j2
+++ b/roles/mailman/templates/mm_cfg.py.j2
@@ -113,7 +113,7 @@ DEFAULT_REPLY_GOES_TO_LIST = 0
 DEFAULT_MAX_DAYS_TO_HOLD = 15
 
 # rimuove le firme Dkim e Dk dalle mail in entrata a mailman
-REMOVE_DKIM_HEADERS = 'YES'
+REMOVE_DKIM_HEADERS = Yes
 
 
 #-------------------------------------------------------------
@@ -141,11 +141,14 @@ ARCHIVE_HTML_SANITIZER = 0
 # 3 = Discard
 DEFAULT_GENERIC_NONMEMBER_ACTION = 2
 
-# added by ale+blicero to limit recipient per send and avoid spam limit measures
-SMTP_MAX_RCPTS = 50
+# Enable VERP probes for better bounce detection, one in 10 emails.
+VERP_PROBES = Yes
+VERP_CONFIRMATIONS = Yes
+VERP_DELIVERY_INTERVAL = 10
 
-# Note - if you're looking for something that is imported from mm_cfg, but you
-# didn't find it above, it's probably in /usr/lib/mailman/Mailman/Defaults.py.
+# Limit recipient per send, avoid spam limit measures and limit blast
+# radius from delivery failures.
+SMTP_MAX_RCPTS = 10
 
 DEFAULT_SUBSCRIBE_POLICY = 3
 DEFAULT_LIST_ADVERTISED = No
-- 
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