# SpamAssassin rules file: header tests # # Please don't modify this file as your changes will be overwritten with # the next update. Use @@LOCAL_RULES_DIR@@/local.cf instead. # See 'perldoc Mail::SpamAssassin::Conf' for details. # # <@LICENSE> # Licensed to the Apache Software Foundation (ASF) under one or more # contributor license agreements. See the NOTICE file distributed with # this work for additional information regarding copyright ownership. # The ASF licenses this file to you under the Apache License, Version 2.0 # (the "License"); you may not use this file except in compliance with # the License. You may obtain a copy of the License at: # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. # # ########################################################################### header HEAD_LONG eval:check_msg_parse_flags('truncated_header') describe HEAD_LONG Message headers are very long # partial messages; currently-theoretical attack # unsurprisingly this hits 0/0 right now. header FRAGMENTED_MESSAGE Content-Type =~ /\bmessage\/partial/i describe FRAGMENTED_MESSAGE Partial message header MISSING_HB_SEP eval:check_msg_parse_flags('missing_head_body_separator') describe MISSING_HB_SEP Missing blank line between message header and body header UNPARSEABLE_RELAY eval:check_relays_unparseable() tflags UNPARSEABLE_RELAY userconf describe UNPARSEABLE_RELAY Informational: message has unparseable relay lines ########################################################################### header NO_REAL_NAME From =~ /^["\s]*\?\s*$/ describe NO_REAL_NAME From: does not include a real name header FROM_BLANK_NAME From =~ /(?:\s|^)"" <\S+>/i describe FROM_BLANK_NAME From: contains empty name ########################################################################### # numeric address rules, these are written to avoid overlap with each other header FROM_ENDS_IN_NUMS From:addr =~ /\D\d{8,}\@/i describe FROM_ENDS_IN_NUMS From: ends in many numbers header FROM_STARTS_WITH_NUMS From:addr =~ /^\d{6,}\S+\@/i describe FROM_STARTS_WITH_NUMS From: starts with many numbers # note: anchored for speed header FROM_HAS_MIXED_NUMS From:addr =~ /^[a-z]+\d+[a-z]+\d+[a-z]+\w*\@/i describe FROM_HAS_MIXED_NUMS From: contains numbers mixed in with letters header FROM_HAS_ULINE_NUMS From =~ /_\S?(?:[a-z]+\w*?\d+|\d+\w*?[a-z]+)\w*\@/i describe FROM_HAS_ULINE_NUMS From: contains an underline and numbers/letters # don't match US/Canada phone numbers: 10 digits optionally preceded by a "1" header FROM_ALL_NUMS From:addr =~ /^(?:\d{1,9}|[02-9]\d{10}|\d{12,})@/ describe FROM_ALL_NUMS From numeric address (except US/Canada phones) # faked addresses tend to come from big public sites, but avoid overlap header __ADDR_NUMS_AT_BIGSITE ALL =~ /^(?:To|From|Cc|Reply-To):\s{0,20})/ [if-unset: unset@unset.unset] describe FROM_NO_USER From: has no local-part before @ sign header TO_NO_USER To =~ /(?:^\@|<\@| \@[^\)<]*$|<>)/ [if-unset: unset@unset.unset] describe TO_NO_USER To: has no local-part before @ sign header TO_EMPTY To =~ /^\s*$/ [if-unset: UNSET] describe TO_EMPTY To: is empty header REPLY_TO_EMPTY Reply-To =~ /^\s*$/ [if-unset: UNSET] describe REPLY_TO_EMPTY Reply-To: is empty header TO_ADDRESS_EQ_REAL To =~ /^\s*"([^"@]+\@[^"@]+)"\s+<\1>\s*$/i describe TO_ADDRESS_EQ_REAL To: repeats address as real name # NOTE: this is what 100% valid undisclosed-recipients mails look like. # If this gets a high score, that's a bug! header UNDISC_RECIPS To =~ /^undisclosed-recipients?:\s*;$/ describe UNDISC_RECIPS Valid-looking To "undisclosed-recipients" # also 100% valid header FAKED_UNDISC_RECIPS To =~ /undisclosed[_ ]*recipient(?:s[^:]|[^s])/i describe FAKED_UNDISC_RECIPS Faked To "Undisclosed-Recipients" header PLING_QUERY Subject =~ /\?.*!|!.*\?/ describe PLING_QUERY Subject has exclamation mark and question mark header SUBJ_HAS_UNIQ_ID eval:check_for_unique_subject_id() describe SUBJ_HAS_UNIQ_ID Subject contains a unique ID header SUBJ_HAS_SPACES Subject =~ /(?:\s{6}|\t\s|\s\t)\S/ describe SUBJ_HAS_SPACES Subject contains lots of white space header SUBJ_ALL_CAPS eval:subject_is_all_caps() describe SUBJ_ALL_CAPS Subject is all capitals header MSGID_SPAM_99X9XX99 MESSAGEID =~ /^<\d\d\d\d\d\d[a-z]\d[a-z][a-z]\d\d\$[a-z][a-z][a-z]\d\d\d\d\d\$\d\d\d\d\d\d\d\d\@/ describe MSGID_SPAM_99X9XX99 Spam tool Message-Id: (99x9xx99 variant) header MSGID_SPAM_ALPHA_NUM MESSAGEID =~ /<[A-Z]{7}-000[0-9]{10}\@[a-z]*>/ describe MSGID_SPAM_ALPHA_NUM Spam tool Message-Id: (alpha-numeric variant) header MSGID_SPAM_CAPS Message-ID =~ /^\s*/ describe MSGID_SPAM_LETTERS Spam tool Message-Id: (letters variant) header MSGID_SPAM_ZEROES MESSAGEID =~ /<0000[0-9a-f]{8}\$0000[0-9a-f]{4}\$0000[0-9a-f]{4}\@/ describe MSGID_SPAM_ZEROES Spam tool Message-Id: (12-zeroes variant) header MSGID_NO_HOST MESSAGEID =~ /\@>(?:$|\s)/m describe MSGID_NO_HOST Message-Id has no hostname header MSGID_OUTLOOK_INVALID eval:check_outlook_message_id() describe MSGID_OUTLOOK_INVALID Message-Id is fake (in Outlook Express format) # catches a few spams missed by MSGID_OUTLOOK_INVALID header __HAS_OUTLOOK_IN_MAILER X-Mailer =~ /\bMSCRM\b|Microsoft (?:CDO|Outlook|Office Outlook)\b/ meta MSGID_DOLLARS (__OE_MSGID_2 && !__HAS_OUTLOOK_IN_MAILER && !__UNUSABLE_MSGID) describe MSGID_DOLLARS Message-Id has pattern used in spam # negative lookahead exempts this MUA from circa 1997-2000 # X-Mailer: Microsoft Outlook Express 4.71.1712.3 # Message-ID: <01bd45da$2649cdc0$LocalHost@andrew> header __MSGID_DOLLARS_OK MESSAGEID =~ /<[0-9a-f]{4,}\$[0-9a-f]{4,}\$[0-9a-f]{4,}\@\S+>/m header __MSGID_DOLLARS_MAYBE MESSAGEID =~ /<\w{4,}\$\w{4,}\$(?!localhost)\w{4,}\@\S+>/mi meta MSGID_DOLLARS_RANDOM __MSGID_DOLLARS_MAYBE && !__MSGID_DOLLARS_OK # bit of a ratware rule, but catches a bit more than just the one ratware header __MSGID_RANDY Message-ID =~ /<[a-z\d][a-z\d\$-]{10,29}[a-z\d]\@[a-z\d][a-z\d.]{3,12}[a-z\d]>/ # heuristic to eliminate most good Message-ID formats header __MSGID_OK_HEX Message-ID =~ /\b[a-f\d]{8}\b/ header __MSGID_OK_DIGITS Message-ID =~ /\d{10}/ header __MSGID_OK_HOST Message-ID =~ /\@(?:\D{2,}|(?:\d{1,3}\.){3}\d{1,3})>/ meta MSGID_RANDY (__MSGID_RANDY && !(__MSGID_OK_HEX || __MSGID_OK_DIGITS || __MSGID_OK_HOST)) describe MSGID_RANDY Message-Id has pattern used in spam # bug 3395 header MSGID_YAHOO_CAPS Message-ID =~ /<[A-Z]+\@yahoo.com>/ describe MSGID_YAHOO_CAPS Message-ID has ALLCAPS@yahoo.com ########################################################################### header __AT_AOL_MSGID MESSAGEID =~ /\@aol\.com\b/i header __FROM_AOL_COM From =~ /\@aol\.com\b/i meta FORGED_MSGID_AOL (__AT_AOL_MSGID && !__FROM_AOL_COM) describe FORGED_MSGID_AOL Message-ID is forged, (aol.com) header __AT_EXCITE_MSGID MESSAGEID =~ /\@excite\.com\b/i header __MY_RCVD_EXCITE Received =~ /\.excite\.com\b/i meta FORGED_MSGID_EXCITE (__AT_EXCITE_MSGID && !__MY_RCVD_EXCITE) describe FORGED_MSGID_EXCITE Message-ID is forged, (excite.com) header __AT_HOTMAIL_MSGID MESSAGEID =~ /\@hotmail\.com\b/i header __FROM_HOTMAIL_COM From =~ /\@hotmail\.com\b/i meta FORGED_MSGID_HOTMAIL (__AT_HOTMAIL_MSGID && (!__FROM_HOTMAIL_COM && !__FROM_MSN_COM && !__FROM_YAHOO_COM)) describe FORGED_MSGID_HOTMAIL Message-ID is forged, (hotmail.com) header __AT_MSN_MSGID MESSAGEID =~ /\@msn\.com\b/i header __FROM_MSN_COM From =~ /\@msn\.com\b/i meta FORGED_MSGID_MSN (__AT_MSN_MSGID && (!__FROM_MSN_COM && !__FROM_HOTMAIL_COM && !__FROM_YAHOO_COM)) describe FORGED_MSGID_MSN Message-ID is forged, (msn.com) header __AT_YAHOO_MSGID MESSAGEID =~ /\@yahoo\.com\b/i header __FROM_YAHOO_COM From =~ /\@yahoo\.com\b/i meta FORGED_MSGID_YAHOO (__AT_YAHOO_MSGID && !__FROM_YAHOO_COM) describe FORGED_MSGID_YAHOO Message-ID is forged, (yahoo.com) ########################################################################### header __MSGID_BEFORE_RECEIVED ALL =~ /\nMessage-Id:.*\nReceived:/si header __MSGID_BEFORE_OKAY Message-Id =~ /\@[a-z0-9.-]+\.(?:yahoo|wanadoo)(?:\.[a-z]{2,3}){1,2}>/ meta MSGID_FROM_MTA_HEADER (__MSGID_BEFORE_RECEIVED && !__MSGID_BEFORE_OKAY) describe MSGID_FROM_MTA_HEADER Message-Id was added by a relay header MSGID_FROM_MTA_ID eval:message_id_from_mta() describe MSGID_FROM_MTA_ID Message-Id for external message added locally header MSGID_FROM_MTA_HOTMAIL Message-Id =~ // describe MSGID_FROM_MTA_HOTMAIL Message-Id was added by a hotmail.com relay header MSGID_LONG MESSAGEID =~ /<.{160,}>|<.{140,}\@|\@.{55,}>/m describe MSGID_LONG Message-ID is unusually long header MSGID_SHORT MESSAGEID =~ /^.{1,15}$|<.{0,4}\@/m describe MSGID_SHORT Message-ID is unusually short header MSGID_MULTIPLE_AT MESSAGEID =~ /<[^>]*\@[^>]*\@/ describe MSGID_MULTIPLE_AT Message-ID contains multiple '@' characters ########################################################################### header DATE_SPAMWARE_Y2K Date =~ /^[A-Z][a-z]{2}, \d\d [A-Z][a-z]{2} [0-6]\d \d\d:\d\d:\d\d [A-Z]{3}$/ describe DATE_SPAMWARE_Y2K Date header uses unusual Y2K formatting header INVALID_DATE Date !~ /^\s*(?:(?i:Mon|Tue|Wed|Thu|Fri|Sat|Sun),\s)?\s*(?:[12]\d|3[01]|0?[1-9])\s+(?i:Jan|Feb|Ma[ry]|Apr|Ju[nl]|Aug|Sep|Oct|Nov|Dec)\s+(?:19[7-9]\d|2\d{3})\s+(?:[01]?\d|2[0-3])\:[0-5]\d(?::(?:[0-5]\d|60))?\s+(?:[AP]M\s+)?(?:[+-][0-9]{4}|UT|[A-Z]{2,3}T)(?:\s+\(.*\))?\s*$/ [if-unset: Wed, 31 Jul 2002 16:41:57 +0200] describe INVALID_DATE Invalid Date: header (not RFC 2822) test INVALID_DATE fail Sat, 31 Dec 2005 23:59:60 -0500 test INVALID_DATE fail Wed, 31 Jul 2002 16:41:57 +0200 test INVALID_DATE ok Sat, 31 Dec 2005 24:00:00 -0500 test INVALID_DATE ok Sat, 31 Dec 2005 23:00:00 test INVALID_DATE ok Thurs, 31 Jul 2002 16:41:57 +0200 # allow +1300, NZ timezone header INVALID_DATE_TZ_ABSURD Date =~ /[-+](?:1[4-9]\d\d|[2-9]\d\d\d)$/ describe INVALID_DATE_TZ_ABSURD Invalid Date: header (timezone does not exist) header INVALID_TZ_CST ALL =~ /[+-]\d\d[30]0(?, see SpamAssassin-talk list 2003-03 # quinlan: 2003-03-23 here are more generic Japanese iso-2022-jp codes # ("not yet acceptance" or "email") + "announcement" # FWIW, according to Peter Evans, this should be sufficient to catch the # UCE tag and a common attempt at evasion (using the "sue" instead of # "mi" Chinese character). header JAPANESE_UCE_SUBJECT Subject =~ /\e\$B.*(?:L\$>5Bz|EE;R%a!<%k)9-9p/ describe JAPANESE_UCE_SUBJECT Subject contains a Japanese UCE tag # quinlan: "advertisement" in Russian KOI8-R # (no longer common, but worth noting in future) #header RUSSIAN_UCE_SUBJECT Subject =~ /\xf0\xe5\xea\xeb\xe0\xec\xf3/ #describe RUSSIAN_UCE_SUBJECT Subject contains a Russian UCE tag # Korean UCE Subject: lines are usually 8-bit, but are occasionally encoded # with quoted-printable or base64. # # \xbc\xba\xc0\xce means "adult" # \xb1\xa4\xb0\xed means "advertisement" # \xc1\xa4\xba\xb8 means "information" # \xc8\xab\xba\xb8 means "publicity" # # Each two byte sequence is one Korean letter; the spaces and periods are # sometimes used to obscure the words. \xb1\xa4\xb0\xed is the most common # tag and is sometimes very obscured so we look harder. # header KOREAN_UCE_SUBJECT Subject =~ /[({[<][. ]*(?:\xbc\xba[. ]*\xc0\xce[. ]*)?(?:\xb1\xa4(?:[. ]*|[\x00-\x7f]{0,3})\xb0\xed|\xc1\xa4[. ]*\xba\xb8|\xc8\xab[. ]*\xba\xb8)[. ]*[)}\]>]/ describe KOREAN_UCE_SUBJECT Subject: contains Korean unsolicited email tag ########################################################################### header FROM_AND_TO_SAME eval:check_for_from_to_same() describe FROM_AND_TO_SAME From and To are the same, but not exactly header FORGED_RCVD_HELO eval:check_for_forged_received_helo() describe FORGED_RCVD_HELO Received: contains a forged HELO header RCVD_HELO_IP_MISMATCH eval:helo_ip_mismatch() describe RCVD_HELO_IP_MISMATCH Received: HELO and IP do not match, but should header RCVD_NUMERIC_HELO eval:check_for_numeric_helo() describe RCVD_NUMERIC_HELO Received: contains an IP address used for HELO header RCVD_ILLEGAL_IP eval:check_for_illegal_ip() describe RCVD_ILLEGAL_IP Received: contains illegal IP address # no legit mailer claims that their mailserver has no name # overlaps with RCVD_DOUBLE_IP*, but let's see how it is scored header RCVD_BY_IP Received =~ /\bby\s+\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(? 1) describe MULTI_FORGED Received headers indicate multiple forgeries header NONEXISTENT_CHARSET Content-Type =~ /charset=.?DEFAULT/ describe NONEXISTENT_CHARSET Character set doesn't exist header CHARSET_FARAWAY_HEADER eval:check_for_faraway_charset_in_headers() describe CHARSET_FARAWAY_HEADER A foreign language charset used in headers tflags CHARSET_FARAWAY_HEADER userconf header X_PRIORITY_HIGH X-Priority =~ /^1/ describe X_PRIORITY_HIGH Sent with 'X-Priority' set to high header X_MSMAIL_PRIORITY_HIGH X-Msmail-Priority =~ /^High/ describe X_MSMAIL_PRIORITY_HIGH Sent with 'X-Msmail-Priority' set to high # this variant is local, using the Received hdr itself... header ROUND_THE_WORLD_LOCAL eval:check_for_round_the_world_received_helo() describe ROUND_THE_WORLD_LOCAL Received: says mail sent around the world (HELO) header MISSING_DATE Date =~ /^UNSET$/ [if-unset: UNSET] describe MISSING_DATE Missing Date: header # this is a quite common false positive, as it's legal to remove a To but leave # a CC. so don't score it high. header MISSING_HEADERS eval:check_for_missing_to_header() describe MISSING_HEADERS Missing To: header header __HAS_SUBJECT exists:Subject meta MISSING_SUBJECT !__HAS_SUBJECT describe MISSING_SUBJECT Missing Subject: header header SUSPICIOUS_RECIPS eval:similar_recipients('0.65','undef') describe SUSPICIOUS_RECIPS Similar addresses in recipient list header SORTED_RECIPS eval:sorted_recipients() describe SORTED_RECIPS Recipient list is sorted by address header GAPPY_SUBJECT Subject =~ /\b(?:[a-z]([-_. =~\/:,*!\@\#\$\%\^&+;\"\'<>\\])\1{0,2}){4}/i describe GAPPY_SUBJECT Subject: contains G.a.p.p.y-T.e.x.t ### header existence tests (description is added automatically) # X-Fix example: NTMail fixed non RFC822 compliant EMail message # # X-PMFLAGS is all caps # # Headers that seem to only be used by a single spamming software and # are found together in the same message: # 1. X-MailingID and X-ServerHost # 2. X-Stormpost-To and X-List-Unsubscribe # # not spammish: X-EM-Registration, X-EM-Version, X-Antiabuse, X-List-Host, # X-Message-Id # bad FP rate: Comment, Date-warning header PREVENT_NONDELIVERY exists:Prevent-NonDelivery-Report describe PREVENT_NONDELIVERY Message has Prevent-NonDelivery-Report header header X_IP exists:X-IP describe X_IP Message has X-IP header header X_LIBRARY exists:X-Library describe X_LIBRARY Message has X-Library header # this rule is case-sensitive header X_MESSAGE_FLAG_ODD ALL =~ /^X-Message-flag:/m describe X_MESSAGE_FLAG_ODD Message has X-Message-flag header (odd case) header __HAS_MIMEOLE exists:X-MimeOLE header __HAS_MSMAIL_PRI exists:X-MSMail-Priority header __HAS_SQUIRRELMAIL_IN_MAILER X-Mailer =~ /SquirrelMail\b/ meta MISSING_MIMEOLE (__HAS_MSMAIL_PRI && !__HAS_MIMEOLE && !__HAS_SQUIRRELMAIL_IN_MAILER) describe MISSING_MIMEOLE Message has X-MSMail-Priority, but no X-MimeOLE header __HAS_X_MAILER exists:X-Mailer header __IS_EXCH X-MimeOLE =~ /Produced By Microsoft Exchange V/ header __HAS_X_PRIORITY exists:X-Priority header __USER_AGENT exists:User-Agent header __X_NEWSREADER exists:X-Newsreader meta PRIORITY_NO_NAME ((__HAS_X_PRIORITY && __HAS_MSMAIL_PRI) && !__HAS_X_MAILER && !__IS_EXCH && !__USER_AGENT && !__X_NEWSREADER) describe PRIORITY_NO_NAME Message has priority, but no user agent name header SUBJ_AS_SEEN Subject =~ /\bAs Seen/i describe SUBJ_AS_SEEN Subject contains "As Seen" header SUBJ_DOLLARS Subject =~ /^\$[0-9.,]+\b/ describe SUBJ_DOLLARS Subject starts with dollar amount header SUBJ_FOR_ONLY Subject =~ /For Only/i describe SUBJ_FOR_ONLY Subject contains "For Only" header SUBJ_FREE_CAP Subject =~ /FREE|F.R.E.E\b/ describe SUBJ_FREE_CAP Subject contains "FREE" in CAPS header SUB_FREE_OFFER Subject =~ /^fre{2,}\b/i describe SUB_FREE_OFFER Subject starts with "Free" header SUBJ_GUARANTEED Subject =~ /^guaranteed|(?-i:GUARANTEE)/i describe SUBJ_GUARANTEED Subject GUARANTEED header SUB_HELLO Subject =~ /^hello\b/i describe SUB_HELLO Subject starts with "Hello" header SUBJ_LIFE_INSURANCE Subject =~ /life\s+insurance/i describe SUBJ_LIFE_INSURANCE Subject includes "life insurance" header SUBJ_YOUR_DEBT Subject =~ /Your (?:Bills|Debt|Credit)/i describe SUBJ_YOUR_DEBT Subject contains "Your Bills" or similar header SUBJ_YOUR_FAMILY Subject =~ /Your Family/i describe SUBJ_YOUR_FAMILY Subject contains "Your Family" header SUBJ_YOUR_OWN Subject =~ /Your Own/i describe SUBJ_YOUR_OWN Subject contains "Your Own" # the real services never HELO as 'foo.com', instead 'mail.foo.com' or # something like that. Note: be careful when expanding this... legit dotcom # HELOers include: hotmail.com, drizzle.com, lockergnome.com. header RCVD_FAKE_HELO_DOTCOM Received =~ /^from (?:msn|yahoo|yourwebsite|lycos|excite|cs|aol|localhost|koreanmail|allexecs|mydomain|juno|eudoramail|compuserve|desertmail|excite|caramail)\.com \(/m describe RCVD_FAKE_HELO_DOTCOM Received contains a faked HELO hostname header ADDRESS_IN_SUBJECT eval:check_for_to_in_subject('address') describe ADDRESS_IN_SUBJECT To: address appears in Subject header LOCALPART_IN_SUBJECT eval:check_for_to_in_subject('user') describe LOCALPART_IN_SUBJECT Local part of To: address appears in Subject header SUBJECT_DIET Subject =~ /\bLose .*(?:pounds|lbs|weight)/i describe SUBJECT_DIET Subject talks about losing pounds header EXTRA_MPART_TYPE Content-Type =~ /(?:\s*multipart\/)?.* type=/i describe EXTRA_MPART_TYPE Header has extraneous Content-type:...type= entry header TO_RECIP_MARKER To =~ /\#recipient\#/ describe TO_RECIP_MARKER To header contains 'recipient' marker # MIME boundary tests; spam tools use distinctive patterns. header MIME_BOUND_DD_DIGITS Content-Type =~ /boundary=\"--\d+\"/ describe MIME_BOUND_DD_DIGITS Spam tool pattern in MIME boundary header MIME_BOUND_DIGITS_7 Content-Type =~ /boundary=\d{9}\.\d{13}/ describe MIME_BOUND_DIGITS_7 Spam tool pattern in MIME boundary header MIME_BOUND_DIGITS_15 Content-Type =~ /boundary=\"\d{15,}\"/ describe MIME_BOUND_DIGITS_15 Spam tool pattern in MIME boundary header MIME_BOUND_MANY_HEX Content-Type =~ /boundary="[\da-f]{8}(?:-[\da-f]{4}){3}-[\da-f]{12}"/ describe MIME_BOUND_MANY_HEX Spam tool pattern in MIME boundary header MIME_BOUND_RKFINDY Content-Type =~ /boundary=\"=_NextPart_2rfkindysadvnqw3nerasdf\"/ describe MIME_BOUND_RKFINDY Spam tool pattern in MIME boundary (rfkindy) # note: the first alternation is anchored for speed header TO_MALFORMED To !~ /(?:^|[^\S"])(?:(?:\"[^\"]+\"|\S+)\@\S+\.\S+|^\s*.+:\s*;|^\s*\"[^\"]+\":\s*;|^\s*\([^\)]*\)\s*$|<\S+(?:\!\S+){1,}>|^\s*$)/ [if-unset: unset@unset.unset] describe TO_MALFORMED To: has a malformed address header ADDR_FREE From =~ /\b(?-i:F)ree(?-i:[ A-Z]).*