Docs: add warning on use of envelope_to_add

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index cea21a18f930f85ac2e8e94a2ff827e0b9fe0a98..f13e58b7915f8130b410664cbbab753913b7a300 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -22498,6 +22498,14 @@ header, Exim has a configuration option (&%envelope_to_remove%&) which requests
 its removal from incoming messages, so that delivered messages can safely be
 resent to other recipients.
 
 its removal from incoming messages, so that delivered messages can safely be
 resent to other recipients.
 

+.new
+&*Note:*& If used on a transport handling multiple recipients
+(the smtp transport unless &%rcpt_max%& is 1, the appendfile, pipe or lmtp
+transport if &%batch_max%& is greater than 1)
+then information about Bcc recipients will be leaked.
+Doing so is generally not advised.
+.wen
+

 
 .option event_action transports string&!! unset
 .cindex events
 
 .option event_action transports string&!! unset
 .cindex events