SECTION(global, incoming)m4_dnl
received_header_text = Received: \
- ${if def:sender_rcvhost {from $sender_rcvhost\n\t} \
- {${if def:sender_ident \
- {from ${quote_local_part:$sender_ident} }}\
+ ${if def:sender_rcvhost \
+ {from $sender_rcvhost\
${if def:sender_helo_name \
- {(helo=$sender_helo_name)\n\t}}}}\
+ { (helo=$sender_helo_name)}}\n\t} \
+ {${if def:sender_ident \
+ {from ${quote_local_part:$sender_ident} }}}}\
by $primary_hostname \
(Exim $version_number)\
${if def:tls_cipher {\n\t} { }}\
acl_smtp_helo = helo
SECTION(acl, misc)m4_dnl
helo:
- require message = The other one has bells on
- verify = helo
+ ## Check that the caller's claimed identity is actually plausible.
+ ## This seems like it's a fairly effective filter on spamminess, but
+ ## it's too blunt a tool. Rather than reject, add a warning header.
+ ## Only we can't do this the easy way, so save it up for use in MAIL.
+ ## Also, we're liable to get a subsequent HELO (e.g., after STARTTLS)
+ ## and we should only care about the most recent one.
+ warn set acl_c_helo_warning = false
+ !condition = \
+ ${if exists {CONF_sysconf_dir/helo.conf} \
+ {${lookup {$sender_helo_name} \
+ partial0-lsearch \
+ {CONF_sysconf_dir/helo.conf} \
+ {${if match_ip \
+ {$sender_host_address} \
+ {$value}}}}}}
+ !verify = helo
+ set acl_c_helo_warning = true
accept
SECTION(acl, mail)m4_dnl
mail:
+ ## If we stashed a warning header about HELO from earlier, we should
+ ## add it now.
+ warn condition = $acl_c_helo_warning
+ add_header = :after_received:X-Distorted-Warning: \
+ BADHELO \
+ Client's HELO doesn't match its IP address.\n\t\
+ HELO name = $sender_helo_name, \
+ address = $sender_host_address
+
## Always allow the empty sender, so that we can receive bounces.
accept senders = :
## Transports for redirection filters.
m4_define(<:FILTER_TRANSPORTS:>,
- <:file_transport = mailbox
+ <:verify = false
+ file_transport = mailbox
directory_transport = maildir
pipe_transport = pipe
reply_transport = reply:>)