diff -Nru postfix-3.3.0/debian/changelog postfix-3.3.0/debian/changelog
--- postfix-3.3.0/debian/changelog	2020-07-10 20:08:22.000000000 +0000
+++ postfix-3.3.0/debian/changelog	2021-08-12 12:43:19.000000000 +0000
@@ -1,3 +1,10 @@
+postfix (3.3.0-1ubuntu0.4) bionic; urgency=medium
+
+  * d/postfix.postinst: tolerate search domain with a leading dot
+    (LP: #1906970)
+
+ -- Paride Legovini <paride@ubuntu.com>  Thu, 12 Aug 2021 14:43:19 +0200
+
 postfix (3.3.0-1ubuntu0.3) bionic; urgency=medium
 
   * d/p/fix_tls_deploy-server-cert.patch: handle missing opt arg (LP: #1881196)
diff -Nru postfix-3.3.0/debian/control postfix-3.3.0/debian/control
--- postfix-3.3.0/debian/control	2018-10-11 20:15:25.000000000 +0000
+++ postfix-3.3.0/debian/control	2021-08-12 12:43:19.000000000 +0000
@@ -1,7 +1,8 @@
 Source: postfix
 Section: mail
 Priority: optional
-Maintainer: LaMont Jones <lamont@debian.org>
+Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com>
+XSBC-Original-Maintainer: LaMont Jones <lamont@debian.org>
 Standards-Version: 4.1.3
 Homepage: http://www.postfix.org
 Build-Depends: debhelper (>= 9.20160709), po-debconf (>= 0.5.0), groff-base, patch, lsb-release, libdb-dev (>=4.6.19), libldap2-dev (>=2.1), liblmdb-dev, libpcre3-dev, default-libmysqlclient-dev | libmysqlclient-dev, libssl-dev (>=0.9.7), libsasl2-dev, libpq-dev, libcdb-dev, dpkg-dev (>= 1.16.1~), libsqlite3-dev, html2text, libicu-dev
diff -Nru postfix-3.3.0/debian/postfix.postinst postfix-3.3.0/debian/postfix.postinst
--- postfix-3.3.0/debian/postfix.postinst	2018-10-11 20:15:25.000000000 +0000
+++ postfix-3.3.0/debian/postfix.postinst	2021-08-12 12:43:19.000000000 +0000
@@ -49,7 +49,7 @@
 	if [ $myhostname = ${myhostname%.*} ]; then
 	    if [ -f /etc/resolv.conf ]; then
 		# The resolver uses the last one found, and ignores the rest
-		mydom=$(sed -n 's/^search[[:space:]]*\([^[:space:]]*\).*/\1/p;s/^domain[[:space:]]*\([^[:space:]]*\).*/\1/p' /etc/resolv.conf | tail -1)
+		mydom=$(sed -n 's/^search[[:space:]]*\.*\([^[:space:]]*\).*/\1/p;s/^domain[[:space:]]*\.*\([^[:space:]]*\).*/\1/p' /etc/resolv.conf | tail -1)
 		myhostname="$myhostname${mydom:+.$mydom}"
 	    else
 		myhostname="$myhostname.UNKNOWN"