As pointed out by tron@, this DESCR file was void.

1 files changed, 21 insertions, 0 deletions

diff --git a/mail/milter-sender/DESCR b/mail/milter-sender/DESCR
index e69de29bb2d..823222b42d9 100644
--- a/mail/milter-sender/DESCR
+++ b/mail/milter-sender/DESCR
@@ -0,0 +1,21 @@
+Spam is the black plague of the Internet world and this Sendmail milter
+attempts to address a small subset of the problem by verifying that the 
+sender's email address is in good standing by performing an SMTP callback 
+to the MX server responsible for the sender's domain. This milter is not 
+intended to be a complete solution to spam and so it should be used in 
+conjunction with other tools such as DNS blacklists and content filters.
+
+To be in good standing, the MX server of the sender must be reachable and
+willing to accept email for the sender from the Delivery Status 
+Notification (DSN) address, which is the null address <> used for error 
+reporting. This particular requirement is similar to using the 
+RFC-Ignornant DSN Blacklist.
+
+During the callback, any failure in establishing an SMTP connection such 
+as no DNS entry or the primary MX server is unreachable, or during the 
+SMTP dialogue such as not accepting the DSN, user unknown, or mail box is 
+full, etc. will result in the incoming mail in question being rejected. 
+In the case of a temporary error during the SMTP dialogue with the 
+sender's MX server, milter-sender will reject the current message with 
+a temporary error code, which the sender is then free to retry again 
+later. DNS lookup and connection problems are treated as temporary errors.