Bug#312361: exim4: Exim incorrectly rejects "'" as illegal character in email address

[Simon Wood]

Package: exim4
Version: 4.50-8
Severity: normal

When replying to an email with a "'" in the address, Exim4 rejects the
address as containing "restricted characters".

According to RFC2822 the "'" is legal.

Example error:
---
* Connecting to SMTP server: localhost ...
[18:48:53] SMTP< 220 slone.mungewell.org ESMTP Exim 4.50 Mon, 06 Jun
2005 18:48:53 -0600
[18:48:53] SMTP> HELO slone.mungewell.org
[18:48:53] SMTP< 250 slone.mungewell.org Hello localhost [127.0.0.1]
[18:48:53] SMTP> MAIL FROM:<simon@mungewell.org>
[18:48:53] SMTP< 250 OK
[18:48:53] SMTP> RCPT TO:<simon'stest@localhost>
[18:48:53] SMTP< 550 restricted characters in address
** error occurred on SMTP session
** Error occurred while sending the message.
---

Strangely enough the offending email had already made it through the
fetchmail/exim system for me to read it in the first place....

Mail client is sylpeed-claws.

Simon.

-- Package-specific info:
Exim version 4.50 #1 built 27-May-2005 08:08:19
Copyright (c) University of Cambridge 2004
Berkeley DB: Sleepycat Software: Berkeley DB 4.2.52: (December  3, 2003)
Support for: iconv() IPv6 GnuTLS
Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dsearch nis nis0 passwd
Authenticators: cram_md5 plaintext
Routers: accept dnslookup ipliteral manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore autoreply lmtp pipe smtp
Fixed never_users: 0
Configuration file is /var/lib/exim4/config.autogenerated
# /etc/exim4/update-exim4.conf.conf
#
# Edit this file and /etc/mailname by hand and execute update-exim4.conf
# yourself or use 'dpkg-reconfigure exim4-config'

dc_eximconfig_configtype='smarthost'
dc_other_hostnames='mungewell.org:mungewell.tele2.net:mungewell.plus.com:mungewell.org'
dc_local_interfaces='127.0.0.1'
dc_readhost='mungewell.org'
dc_relay_domains=''
dc_minimaldns='false'
dc_relay_nets=''
dc_smarthost='shawmail.lb.shawcable.net'
#dc_smarthost='relay.plus.net'
CFILEMODE='644'
dc_use_split_config='false'
dc_hide_mailname='true'
dc_mailname_in_oh='true'
mailname:mungewell.org

-- System Information:
Debian Release: 3.1
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: i386 (i586)
Shell:  /bin/sh linked to /bin/bash
Kernel: Linux 2.4.31
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)

Versions of packages exim4 depends on:
ii  exim4-base                    4.50-8     support files for all exim MTA (v4
ii  exim4-daemon-light            4.50-8     lightweight exim MTA (v4) daemon

-- no debconf information