Hi! I've tried to block external emails coming to our mailing lists defined in LDAP.

I've already tried the following means:

1) "LDAP_SOURCE mailsource" setting in ldapaliasrc, then "mailsource: local" attribute on mailing lists in LDAP - it doesn't work as documented, Courier's ldapaliasd does searches on that attribute (&(mail=all)(mailsource=esmtp)), but still delivers to those lists afterwards; 2) Delivery checks in maildroprc with forward to a moderator - unacceptable, the moderator account receives as many copies of each mail as there were members in a list; the envoronment variable AUTHENTICATED isn't available to test whether the user authenticated with SMTP AUTH; 3) Alias filtering account specified in /etc/courier/aliasfilteracct - it doesn't seem to work for LDAP aliases 4) Global perlfilter - hard to debug, dangerous and still doesn't work...

Ad. 4): I can see filter processes: courier 8229 0.0 0.0 4464 456 ? S 20:59 0:00 perlfilter

Filtering is enabled:

# cat /etc/courier/enablefiltering esmtp local

But the following code from the filterdata() function doesn't seem to give any results, as if it wasn't run at all:

<snip> # Here's where the custom content filter is implemented. Use filehandles # so that cleanup's automatic.

my $fh=new IO::File "< $filename";

return "" unless defined $fh;

my $line; my $to_private_list = 0; my $from_admin_account = 0;

my $logfh = new IO::File ">>/var/spool/courier/tmp/perlfilterlog.txt";

while ( defined ($line=<$fh>)) { chomp $line; last if $line eq ""; # End of headers

if ( $line =~ /^To:.+mailinglist\@.+$/i ) { $to_private_list = 1; } if ( $line =~ /^From:.+admin\.account@domain\.com.+$/i ) { print $logfh "From admin"; $from_admin_account = 1; }

if ($to_private_list && ! $from_admin_account) { return "550 Access to list denied." } return ""; </snip>