To check if a maildrop mailfilter recipe is syntactically valid you can pass /dev/null to it:
$ cat /dev/null|/usr/lib/courier/bin/maildrop .mailfilter
If it is invalid maildrop shows an according error message. See also the maildrop mailing list.
To check if a maildrop mailfilter recipe is syntactically valid you can pass /dev/null to it:
$ cat /dev/null|/usr/lib/courier/bin/maildrop .mailfilter
If it is invalid maildrop shows an according error message. See also the maildrop mailing list.