[evolution] Add a comment about Bcc headers to searchtypes.xml.

[Matthew Barnes <mbarnes src gnome org>]

commit fd736a6edee20000997105f4ba45094a7a7dae7e
Author: Matthew Barnes <mbarnes redhat com>
Date:   Fri Mar 16 13:46:58 2012 -0400

    Add a comment about Bcc headers to searchtypes.xml.

 mail/searchtypes.xml |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/mail/searchtypes.xml b/mail/searchtypes.xml
index c74f58c..680fd7e 100644
--- a/mail/searchtypes.xml
+++ b/mail/searchtypes.xml
@@ -48,6 +48,10 @@
    <input type="string" name="sender"/>
  </part>
 
+ <!-- NOTE: Do not include Bcc addresses in this search until Camel
+            includes Bcc addresses in its summary database.  Otherwise
+            it kills our search performance by forcing entire messages
+            to be downloaded just to examine their Bcc headers. -->
  <part name="to">
    <title>Recipients</title>
    <input type="optionlist" name="recipient-type">