smtp: Support UTF-8 based host names in the MAIL command

Non-ASCII host names will be ACE encoded if IDN is supported.

tests/data/Makefile.inc

@@ -108,7 +108,7 @@ test918 test919 test920 test921 test922 test923 test924 test925 test926 \
 test927 test928 test929 test930 test931 test932 test933 test934 test935 \
 test936 test937 test938 test939 test940 test941 test942 test943 test944 \
 test945 test946 test947 test948 test949 test950 test951 test952 test953 \
-test954 test955 test956 test957 test958 test959 test960 test961 \
+test954 test955 test956 test957 test958 test959 test960 test961 test962 \
 \
 test1000 test1001 test1002 test1003 test1004 test1005 test1006 test1007 \
 test1008 test1009 test1010 test1011 test1012 test1013 test1014 test1015 \

tests/data/test959

@@ -16,6 +16,9 @@ SMTP
 <server>
 smtp
 </server>
+<features>
+!idn
+</features>
 <setenv>
 LC_ALL=en_US.UTF-8
 LC_CTYPE=en_US.UTF-8

tests/data/test962

@@ -0,0 +1,62 @@
+<testcase>
+<info>
+<keywords>
+SMTP
+IDN
+</keywords>
+</info>
+
+#
+# Server-side
+<reply>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+smtp
+</server>
+<features>
+idn
+</features>
+<setenv>
+LC_ALL=en_US.UTF-8
+LC_CTYPE=en_US.UTF-8
+</setenv>
+<precheck>
+perl -MI18N::Langinfo=langinfo,CODESET -e 'die "Needs a UTF-8 locale" if (lc(langinfo(CODESET())) ne "utf-8");'
+</precheck>
+ <name>
+SMTP without SMTPUTF8 support - UTF-8 based sender (host part only)
+ </name>
+<stdin>
+From: different
+To: another
+
+body
+</stdin>
+<command>
+smtp://%HOSTIP:%SMTPPORT/962 --mail-rcpt recipient@example.com --mail-from sender@åäö.se -T -
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<protocol>
+EHLO 962
+MAIL FROM:<sender@xn--4cab6c.se>
+RCPT TO:<recipient@example.com>
+DATA
+QUIT
+</protocol>
+<upload>
+From: different
+To: another
+
+body
+.
+</upload>
+</verify>
+</testcase>