Bug#291832: exim4-config: !verify=reverse_host_lookup logs but does not warn on defer

[Marc Sherman]

Package: exim4-config
Version: 4.34-10
Severity: wishlist

The stock exim4-config includes a (commented out) block that does
reverse DNS verification in the ACLs using !verify=reverse_host_lookup.
In the case of a defer (ie: a DNS timeout), this logs but does not
actually include the warning header in the message.

Replacing the ACL block with the following will include a header in the
case of a defer as well as a failure.  I've found that DNS timeouts are
much more frequently due to spammers setting up intentionally broken
authoritative DNS servers than they are due to my own DNS server being 
temporarily busted, so getting the header in a message in case of a
defer is useful.

  # MSS: If sender_host_address is defined, it's a remote call.  If
  # sender_host_name is not defined, then reverse lookup failed.  Use
  # this
  # instead of !verify = reverse_host_lookup to catch deferrals as well
  # as
  # outright failures.
  #
  warn message = X-Host-Lookup-Failed: Reverse DNS lookup failed for $sender_hos
t_address ($if eq{$host_lookup_failed}{1}{failed}{deferred}})
       condition = ${if and{{def:sender_host_address}{!def:sender_host_name}}\
                        {yes}{no}}


-- Package-specific info:
Exim version 4.34 #1 built 05-Jan-2005 11:07:49
Copyright (c) University of Cambridge 2004
Berkeley DB: Sleepycat Software: Berkeley DB 3.2.9: (May 26, 2004)
Support for: iconv() IPv6 PAM Perl GnuTLS
Lookups: lsearch wildlsearch nwildlsearch iplsearch cdb dbm dbmnz dnsdb dsearch ldap ldapdn ldapm mysql nis nis0 passwd pgsql
Authenticators: cram_md5 plaintext spa
Routers: accept dnslookup ipliteral iplookup manualroute queryprogram redirect
Transports: appendfile/maildir/mailstore/mbx autoreply lmtp pipe smtp
Fixed never_users: 0
Contains exiscan-acl patch revision 21 (c) Tom Kistner [http://duncanthrax.net/exiscan/]
Configuration file is /var/lib/exim4/config.autogenerated

-- System Information:
Debian Release: 3.1
  APT prefers testing
  APT policy: (900, 'testing'), (300, 'unstable')
Architecture: i386 (i686)
Kernel: Linux 2.6.8-2-k7
Locale: LANG=en_CA, LC_CTYPE=en_CA (charmap=ISO-8859-1)

Versions of packages exim4-config depends on:
ii  adduser                     3.59         Add and remove users and groups
ii  debconf [debconf-2.0]       1.4.30.11    Debian configuration management sy
ii  passwd                      1:4.0.3-30.7 Change and administer password and

-- debconf information:
  exim4/dc_noalias_regenerate: false
* exim4/dc_smarthost: mail.magma.ca
* exim4/dc_relay_domains:
* exim4/dc_relay_nets:
* exim4/mailname: projectile.ca
* exim4/dc_local_interfaces:
* exim4/dc_minimaldns: false
  exim4/exim3_upgrade: true
* exim4/dc_other_hostnames: lab403.com:groundworksdesign.ca:redthreaddesign.ca
* exim4/dc_eximconfig_configtype: internet site; mail is sent and received directly using SMTP
  exim4/no_config: true
* exim4/hide_mailname: false
* exim4/dc_postmaster: msherman
* exim4/dc_readhost: projectile.ca
* exim4/use_split_config: false
  exim4/exim4-config-title: