I would urge other sysadmins out there to not block mail based on rDNS. That eliminates some legitimate use cases for e-mail. Spamhaus and greylisting work very well for me.
> On 2017, Aug 4, at 2:07 PM, John Troy <[email protected]> wrote: > > Hi all, > > I've been getting a lot this type of spam lately myself, but I'm just hosting > my own email, so I've been (shamefully) ignoring it... I'm curious how the > other OpenSMTPD users are dealing with rDNS mismatches on incoming mail. Are > you using SpamAssassin? > > Thanks, > John > > On 07/29/2017 07:53 AM, Craig Skinner wrote: >> Hi, >> >> On Sat, 29 Jul 2017 06:12:31 +0500 Sandro Cardelli <[email protected]> >> spammed: >>> Received: from rptf.pisem.net (221.176.221.70 [221.176.221.70]) >>> by mx1.poolp.org (OpenSMTPD) with ESMTP id 7999980e >>> for <[email protected]>; >>> Sat, 29 Jul 2017 03:12:32 +0200 (CEST) >>> From: "Sandro Cardelli" <[email protected]> >>> To: "misc" <[email protected]> >>> Subject: Re: have you heard the news? >>> Date: Sat, 29 Jul 2017 06:12:31 +0500 >>> Message-ID: <[email protected]> >> >> <hostmaster@palm:/tmp 0>$ host 221.176.221.70 >> Host 70.221.176.221.in-addr.arpa. not found: 3(NXDOMAIN) >> >> >> Could client (r)DNS client hostname restrictions be built into OpenSMTPd? >> >> >> This sort of spam is stopped dead by Postfix with these built in settings: >> >> smtpd_helo_restrictions = >> reject_invalid_helo_hostname >> reject_non_fqdn_helo_hostname >> reject_unknown_helo_hostname >> >> smtpd_client_restrictions = >> reject_unknown_client_hostname >> >> smtpd_sender_restrictions = >> reject_non_fqdn_sender >> reject_unlisted_sender >> reject_unknown_sender_domain >> >> smtpd_recipient_restrictions = >> reject_non_fqdn_recipient >> reject_unlisted_recipient >> reject_unknown_recipient_domain >> >> >> Cheers! >> > > > -- > You received this mail because you are subscribed to [email protected] > To unsubscribe, send a mail to: [email protected] > -- You received this mail because you are subscribed to [email protected] To unsubscribe, send a mail to: [email protected]
