SMTP qmail via Port 25 with RBL

[Sellighsphire]

Hi!

We are using qmail on server and want to activate Spamhaus RBL.
This works fine but sending mails via smtp on port 25 failed because mails are marked as spam.
Using port 465 or 587 isn't a good choice because many users has to change the port on their clients.
We want to disable RBL check with smtp. Is this possible? How do we do?

Thanks a lot for your help
Jens