How are you using maildrop? Where, in processing your incoming
email, is it invoked? Your question doesn't say.
I'm trying to setup Maildrop filtering for many reasons (adding
disclaimer, put spam email in an ad hoc folder and so on).
I'm using a Postfix+MySQL+Courier-IMAP platform.
I'm using virtual user and maildrop. Herre the relative
entry in the
master.cf file:
.
.
.
virtual unix - n n - - virtual .
.
.
maildrop unix - n n - - pipe .
.
.
Based on this information and your previous emails you need
to take your program to a postfix support as your past emails
indicate you are using the virtual transport, not the
maildrop transport. Neither of which have anything to do
with courier maildrop.