diff --git a/Makefile b/Makefile
index 4d17a02..8a54322 100644
--- a/Makefile
+++ b/Makefile
@@ -26,12 +26,13 @@ ${DEB}: control copyright changelog.Debian postinst postrm proxmox-release-5.x.p
 	mkdir -p build/usr/share/doc/${PACKAGE}
 	mkdir -p build/etc/apt/trusted.gpg.d
 	install -m 0644 proxmox-release-5.x.pubkey build/etc/apt/trusted.gpg.d/proxmox-ve-release-5.x.gpg
-	echo "/etc/apt/trusted.gpg.d/proxmox-ve-release-5.x.gpg" > build/DEBIAN/conffiles
+	install -m 0644 conffiles build/DEBIAN/conffiles
 	install -m 0644 control build/DEBIAN/control
 	install -m 0755 postinst build/DEBIAN/postinst
 	install -m 0755 postrm build/DEBIAN/postrm
 	install -m 0644 copyright build/usr/share/doc/${PACKAGE}
 	install -m 0644 changelog.Debian build/usr/share/doc/${PACKAGE}
+	install -D -m 0644 grub-defaults.cfg build/etc/default/grub.d/proxmox-mailgateway.cfg
 	gzip -n --best build/usr/share/doc/${PACKAGE}/changelog.Debian
 	dpkg-deb --build build ${DEB}
 	lintian ${DEB}
diff --git a/conffiles b/conffiles
new file mode 100644
index 0000000..d2cfe33
--- /dev/null
+++ b/conffiles
@@ -0,0 +1,2 @@
+/etc/apt/trusted.gpg.d/proxmox-ve-release-5.x.gpg
+/etc/default/grub.d/proxmox-mailgateway.cfg
diff --git a/grub-defaults.cfg b/grub-defaults.cfg
new file mode 100644
index 0000000..8862739
--- /dev/null
+++ b/grub-defaults.cfg
@@ -0,0 +1 @@
+GRUB_DISTRIBUTOR="Proxmox Mail Gateway"