From 3c8dcd902a4bb0d545681bd01a436f495c40cc04 Mon Sep 17 00:00:00 2001
From: Maximilian Bosch <maximilian@mbosch.me>
Date: Thu, 3 Jun 2021 13:10:23 +0200
Subject: [PATCH] nixos/mail-exporter: add note about rspamd marking probe
 mails as spam

(cherry picked from commit ba9768f3143c728a47515d0548025a103fca9013)
---
 .../monitoring/prometheus/exporters/mail.nix   | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/nixos/modules/services/monitoring/prometheus/exporters/mail.nix b/nixos/modules/services/monitoring/prometheus/exporters/mail.nix
index 18c5c4dd162..7e196149fbb 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters/mail.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters/mail.nix
@@ -112,6 +112,24 @@ let
       '';
       description = ''
         List of servers that should be probed.
+
+        <emphasis>Note:</emphasis> if your mailserver has <citerefentry>
+        <refentrytitle>rspamd</refentrytitle><manvolnum>8</manvolnum></citerefentry> configured,
+        it can happen that emails from this exporter are marked as spam.
+
+        It's possible to work around the issue with a config like this:
+        <programlisting>
+        {
+          <link linkend="opt-services.rspamd.locals._name_.text">services.rspamd.locals."multimap.conf".text</link> = '''
+            ALLOWLIST_PROMETHEUS {
+              filter = "email:domain:tld";
+              type = "from";
+              map = "''${pkgs.writeText "allowmap" "domain.tld"}";
+              score = -100.0;
+            }
+          ''';
+        }
+        </programlisting>
       '';
     };
   };