--- imap/pop3d.dist.in
+++ imap/pop3d.dist.in
@@ -28,6 +28,25 @@
 
 MAXPERIP=4
 
+##NAME: POP3_ULIMITD:0
+#
+# POP3_ULIMITD sets the maximum size of the data segment of the server
+# process.  The value of POP3_ULIMITD is simply passed to the "ulimit -d"
+# command (or ulimit -v).  The argument to ulimi sets the upper limit on the
+# size of the data segment of the server process, in kilobytes.  The default
+# value of 65536 sets a very generous limit of 64 megabytes, which should
+# be more than plenty for anyone.
+#
+# This feature is used as an additional safety check that should stop
+# any potential denial-of-service attacks that exploit any kind of
+# a memory leak to exhaust all the available memory on the server.
+# It is theoretically possible that obscenely huge folders will also
+# result in the server running out of memory when doing server-side
+# sorting (by my calculations you have to have at least 100,000 messages
+# in a single folder, for that to happen).
+
+POP3_ULIMITD=65536
+
 ##NAME: POP3AUTH:1
 #
 # To advertise the SASL capability, per RFC 2449, uncomment the POP3AUTH