plesk to not write domains into rcpthost file

[futureweb]

Hello,

we are using an external anti junk mail provider, that we let all our mails go through.

Now to stop spammer to bypass mx records and send mail directly, I have to empty out the rctphost file.

How do I get Plesk to either not write domains into the rctphost file, or probably write the domains into another file.

Or another thing I could think of - telling Qmail to use another file as rcpthost, but seems I can't as the control directory is necessary for other stuff.

The reason is - that smtp authentification still needs to work for outgoing mail, which works ok, as long as the rcpthost file is empty.

Any suggestions?

Thanks
Patrick