Thank you Jan-Pieter, As a matter of fact I have a range smtp-vbrnn.xs4all.nl in the whitelist. I knew about xs4all as I often receive mail from there. What I didn't knew/hoped was this behaviour from other ISP's. So this is typically something I overlooked.
I will see into John Rudd's suggestion. kind regards, Frank On Sunday 16 July 2006 12:37, Jan-Pieter Cornet wrote: > On Sun, Jul 16, 2006 at 11:02:06AM +0200, ML Listuser wrote: > > So I created a filter_relay which, on a connect-request, tries to > > establish a telnet/smtp connection with the calling host and if it does > > _not_ succeed, rejects the connection with '554 <my mx> ESMTP not > > accepting messages'. > > You wouldn't be able to receive mail from us: xs4all.nl (and all > customers and customer domains). Several other largish ISPs might > have the same problem. > > Our outgoing smtp server is actually a loadbalancer, spreading > the connections over several client machines. The client machines > cannot receive incoming SMTP connections, since they are for outgoing > SMTP only. > > This setup is not unusual, separating outgoing and incoming SMTP > servers; And often the outgoing SMTP servers will not allow incoming > connections. > > John Rudd's suggestion might make more sense, blocking on dynamic- > looking hostnames. However that isn't ideal either, because it will > block wellbehaved SOHO mailservers on DSL lines from really crappy > providers (without properly functioning outgoing mailservers, > and without a possibility to change the reverse DNS name). _______________________________________________ NOTE: If there is a disclaimer or other legal boilerplate in the above message, it is NULL AND VOID. You may ignore it. Visit http://www.mimedefang.org and http://www.roaringpenguin.com MIMEDefang mailing list MIMEDefang@lists.roaringpenguin.com http://lists.roaringpenguin.com/mailman/listinfo/mimedefang