-The third way is controlled by the "plussed_user" value of "masquerade:" line of
-mts.conf. When that's turned on, setting the $USERPLUS environment variable
-will result in its value being tacked onto the user's login name, following
-a '+' sign. For instance, if I set $USERPLUS to "www", my "From:" line will
-contain "Dan Harkless <dan+www@machine.company.com>" (or "Dan.Harkless+www" if
-I'm using mmailid masquerading as well). Recent versions of sendmail
-automatically deliver all mail sent to \fIuser\fR+\fIstring\fR to \fIuser\fR.
+The third way is controlled by the "user_extension" value of "masquerade:" line
+of mts.conf. When that's turned on, setting the \fB$USERNAME_EXTENSION\fR
+environment variable will result in its value being appended the user's login
+name. For instance, if I set \fB$USERNAME_EXTENSION\fR to "+www", my "From:"
+line will contain "Dan Harkless <dan+www@machine.company.com>" (or
+"Dan.Harkless+www" if I'm using mmailid masquerading as well). Recent versions
+of sendmail automatically deliver all mail sent to \fIuser\fR+\fIstring\fR to
+\fIuser\fR. qmail has a similar feature which uses '\-' as the delimiter by
+default, but can use other characters as well.