Transport: permit an empty string for the transport_filter option. Bug 1714

[exim.git] / doc / doc-docbook / spec.xfpt

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index b0b1585fe5c2e08abc4ec6c5bf1a5dd3c506ceeb..af57d9b8566f516dd782e00c0ab72853618a556c 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -20717,6 +20717,9 @@ headers that some sites insist on.
 This option sets up a filtering (in the Unix shell sense) process for messages
 at transport time. It should not be confused with mail filtering as set up by
 individual users or via a system filter.
+.new
+If unset, or expanding to an empty string, no filtering is done.
+.wen
 
 When the message is about to be written out, the command specified by
 &%transport_filter%& is started up in a separate, parallel process, and