[Dovecot] OT: DNS-Problem with Mailnglist-Server

[Nick Edwards]

On Mon, May 30, 2011 at 10:11 PM, Henrik Larsson <dovecot-user at spambox.dk>wrote:

> which leads to postfix complaining:
>>
>> May 30 13:28:39 mail postfix/smtpd[25014]: NOQUEUE: reject_warning: RCPT
>> from unknown[193.210.130.67]: 450 4.7.1 Client host rejected: cannot
>> find your reverse hostname, [193.210.130.67];
>> from=<dovecot-bounces at dovecot.org> to=<hanns at hannsmattes.de> proto=ESMTP
>> helo=<dovecot.org>
>>
>
> If your are checking for reverse hostname and won't accept e-mails if this
> is not present you will reject a lot of legitimate mail.
>


This also stops more spam than the good mail it blocks, when people get
blocked for this, they should complain to their ISP, why should we accept
NON RFC compliant mail servers because the sys admin has not got around to
reading dns 101?

Yes I know some ISP dont care and shrug their shoulders, I tell the people
who complain to postmaster address to find an ISP who can set up their
networks and cares about their users!

My employer does not pay me to sit here and update the whitelist files every
15 minutes because of some ISP who doesn't care about their users sending
mail, and at my last employer a  couple of years ago, we did the sums, 92%
of spam stopped by rejecting no dns hosts! even here I still see it

mx-in1 ~$ cat maillog | grep -c "cannot find your hostname"
5328

mx-in2 ~$ cat maillog | grep -c "cannot find your hostname"
7041

in only 20 hours since logs rolled!!!!!!!


enjoy your spam :->