commit c31d5dd: [Minor] Update regexp for R_UNDISC_RCPT

[Anton Yuzhaninov]

Author: Anton Yuzhaninov
Date: 2020-12-14 19:31:22 +0000
URL: https://github.com/rspamd/rspamd/commit/c31d5ddde33f2fb1bd410cf97fecdd2845bc5053 (refs/pull/3576/head)

[Minor] Update regexp for R_UNDISC_RCPT
Match more variations for undisclosed-recipients, but don't match when
it is used as a lame real name.

---
 rules/regexp/headers.lua | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/rules/regexp/headers.lua b/rules/regexp/headers.lua
index b760b802e..c47205fea 100644
--- a/rules/regexp/headers.lua
+++ b/rules/regexp/headers.lua
@@ -106,9 +106,17 @@ reconf['MISSING_TO'] = {
 }
 
 -- Detects undisclosed recipients
-local undisc_rcpt = 'To=/^<?undisclosed[- ]recipient/Hi'
 reconf['R_UNDISC_RCPT'] = {
-  re = string.format('(%s)', undisc_rcpt),
+  -- match:
+  -- To: undisclosed-recipients:;
+  -- To: Undisclosed recipients:;
+  -- To: undisclosed-recipients: ;
+  -- To: <Undisclosed-Recipient:;>
+  -- To: "undisclosed-recipients (utajeni adresati)": ;
+  -- To: Undisclosed recipients:
+  -- but do not match:
+  -- Undisclosed Recipient <user at example.org>
+  re = [[To=/^[<"]?undisclosed[- ]recipients?\b.*:/i{header}]],
   score = 3.0,
   description = 'Recipients are absent or undisclosed',
   group = 'headers',