+ zlib
+ ----
+
+ zlib is an extremely popular compression library. It is used
+ by Xapian, so if you installed that you will already have
+ zlib. You may need to install the zlib headers separately.
+
+ Notmuch needs the transparent write feature of zlib introduced
+ in version 1.2.5.2 (Dec. 2011).
+
+ zlib is available from http://zlib.net
+