Slightly OT: Postfix smtpd restrictions
drew.marshall at trunknetworks.com
Fri Jun 25 09:01:47 IST 2010
On 24 Jun 2010, at 12:57, Jason Ede wrote:
> This is purely MTA based, but since a lot of users here run postfix...
> How have others found reject_unknown_reverse_client_hostname and the
> more harsh reject_unknown_client_hostname in postfix? I’m debating
> implementing them here and wonder if others have found them
> problematic or useful? I thinking they should be good for weeding
> out spam emails and I can’t see that they should catch legitimate
> senders, but want to be sure
I have to be honest, I ran this for a short while in warn mode and
found that the number of people with mis-configured PTR records is
huge (In the UK). For example, BT won't let anyone change their PTR,
so EHLO/ HELO is always going to be a mismatch for these. Most people
running Exchange 'naked' to the Internet end up having a EHLO as
<name>.local or some such other non existent TLD so that ends up not
matching either and so it goes on.
As ever YMMV but for me, I found other ways to combat spam coming from
these sorts of connections such as RBLs etc.
In line with our policy, this message has been scanned for viruses and dangerous content.
Our email policy can be found at www.trunknetworks.com/policy
Trunk Networks Limited is registered in Scotland with registration number: SC351063
Registered Office 55-57 West High Street Inverurie AB51 3QQ
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the MailScanner