diff -Nru fetchmail-6.6.3/debian/changelog fetchmail-6.6.3/debian/changelog
--- fetchmail-6.6.3/debian/changelog	2026-04-19 17:03:43.000000000 +0100
+++ fetchmail-6.6.3/debian/changelog	2026-05-06 00:36:24.000000000 +0100
@@ -1,3 +1,13 @@
+fetchmail (6.6.3-2.1) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * Stop deleting system user on purge to avoid potential issues with
+    recycled UIDs
+  * Switch to sysusers.d and tmpfiles.d instead of manual scripting in
+    maintainer scripts
+
+ -- Luca Boccassi <bluca@debian.org>  Wed, 06 May 2026 00:36:24 +0100
+
 fetchmail (6.6.3-2) unstable; urgency=medium
 
   [ Christian Marillat <marillat@deb-multimedia.org> ]
diff -Nru fetchmail-6.6.3/debian/control fetchmail-6.6.3/debian/control
--- fetchmail-6.6.3/debian/control	2025-10-03 18:45:55.000000000 +0100
+++ fetchmail-6.6.3/debian/control	2026-05-06 00:30:41.000000000 +0100
@@ -2,14 +2,14 @@
 Section: mail
 Priority: optional
 Maintainer: Laszlo Boszormenyi (GCS) <gcs@debian.org>
-Build-Depends: debhelper-compat (= 13), pkgconf, flex, libssl-dev (>= 3.1.4), bison, libkrb5-dev, libgssglue-dev
+Build-Depends: debhelper-compat (= 13), dh-sequence-installsysusers, pkgconf, flex, libssl-dev (>= 3.1.4), bison, libkrb5-dev, libgssglue-dev
 Standards-Version: 4.7.2
 Homepage: https://www.fetchmail.info
 
 Package: fetchmail
 Architecture: any
 Pre-Depends: ${misc:Pre-Depends}
-Depends: ${shlibs:Depends}, ${misc:Depends}, adduser
+Depends: ${shlibs:Depends}, ${misc:Depends}
 Breaks: logcheck (<< 1.1.1-9), fetchmail-ssl (<= 6.2.5-12)
 Conflicts: fetchmail-common
 Replaces: fetchmail-common, fetchmail-ssl
diff -Nru fetchmail-6.6.3/debian/fetchmail.postinst fetchmail-6.6.3/debian/fetchmail.postinst
--- fetchmail-6.6.3/debian/fetchmail.postinst	2019-09-02 19:33:18.000000000 +0100
+++ fetchmail-6.6.3/debian/fetchmail.postinst	1970-01-01 01:00:00.000000000 +0100
@@ -1,31 +0,0 @@
-#!/bin/sh
-#
-# Postinst script for fetchmail
-# $Id: fetchmail.postinst 469 2008-05-18 12:47:05Z nion $
-#
-
-set -e
-
-# Create fetchmail user and its homedir if we may need it
-if ! getent passwd fetchmail >/dev/null; then
-	adduser --system --ingroup nogroup --home /var/lib/fetchmail \
-	--shell /bin/false --disabled-password fetchmail
-fi
-
-# if the login shell is not /bin/false, change this, see #481727
-LOGINSH=$(getent passwd fetchmail | cut -d ':' -f 7)
-if [ "x$LOGINSH" != "x/bin/false" ]; then
-	chsh -s /bin/false fetchmail
-fi
-
-if ! [ -d /var/lib/fetchmail ]; then
-    mkdir -p /var/lib/fetchmail
-fi
-chmod 700 /var/lib/fetchmail
-chown -h -R fetchmail:nogroup /var/lib/fetchmail
-
-#DEBHELPER#
-
-exit 0
-
-# vim:ts=4:sw=4:
diff -Nru fetchmail-6.6.3/debian/fetchmail.postrm fetchmail-6.6.3/debian/fetchmail.postrm
--- fetchmail-6.6.3/debian/fetchmail.postrm	2016-11-03 21:07:11.000000000 +0000
+++ fetchmail-6.6.3/debian/fetchmail.postrm	2026-05-06 00:30:02.000000000 +0100
@@ -17,14 +17,6 @@
 	# Remove other cruft
 	rm -f /var/mail/.fetchmail-UIDL-cache >/dev/null 2>&1 || true
 	rm -rf /var/run/fetchmail >/dev/null 2>&1 || true
-
-	# Remove user fetchmail
-	fetchmailhome=`getent passwd fetchmail | cut -d : -f 6`
-	rm -f "$fetchmailhome/.fetchids" >/dev/null 2>&1 || true
-	rm -f "$fetchmailhome/.fetchmail-UIDL-cache" >/dev/null 2>&1 || true
-	rm -f "$fetchmailhome/.fetchmail.pid" >/dev/null 2>&1 || true
-	userdel fetchmail || true
-	rmdir "$fetchmailhome" >/dev/null 2>&1 || true
 fi
 
 exit 0
diff -Nru fetchmail-6.6.3/debian/fetchmail.sysusers fetchmail-6.6.3/debian/fetchmail.sysusers
--- fetchmail-6.6.3/debian/fetchmail.sysusers	1970-01-01 01:00:00.000000000 +0100
+++ fetchmail-6.6.3/debian/fetchmail.sysusers	2026-05-06 00:27:56.000000000 +0100
@@ -0,0 +1 @@
+u! fetchmail -:nogroup - /var/lib/fetchmail /bin/false