From owner-freebsd-questions@freebsd.org Sun Mar 31 06:12:35 2019 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5A22E154EF89 for ; Sun, 31 Mar 2019 06:12:35 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.75]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "mout.kundenserver.de", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id E47386B82F for ; Sun, 31 Mar 2019 06:12:33 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from r56.edvax.de ([92.193.229.77]) by mrelayeu.kundenserver.de (mreue106 [212.227.15.183]) with ESMTPA (Nemesis) id 1MulZl-1gtlvv3fDH-00rlMJ; Sun, 31 Mar 2019 08:12:25 +0200 Date: Sun, 31 Mar 2019 08:12:24 +0200 From: Polytropon To: RW Cc: RW via freebsd-questions Subject: Re: Why is Sendmail still around? Message-Id: <20190331081224.f6e4cf61.freebsd@edvax.de> In-Reply-To: <20190330145410.17cfd72d@gumby.homeunix.com> References: <4101a1092141b58e05ef7552278b15ff@kathe.in> <20190329121212.1f12fed7.freebsd@edvax.de> <20190329140110.3c7102ef876f3a1e58ea467b@sohara.org> <20190330034114.54ae2511.freebsd@edvax.de> <20190330145410.17cfd72d@gumby.homeunix.com> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:G6LRmQvKMjzATmYhv/9EL543JLmk7JRZkkwAi7aK2nGP92oA8MG MgCbXcPoCum/dkuUEPAe+Ax/tuEfAL0b0b951VgOuOlaCctF2VRuj41xaPUS5UobtdoBkQk BsOOJBzswUVn1nlpUV9Li5kekPRiUz4LXTuW5YybTrNj/QUGMV2a5knCXtIXCbPyEj7uaxC 94AwHOotHGuvuoGA49HWg== X-Spam-Flag: NO X-UI-Out-Filterresults: notjunk:1;V03:K0:ZmkEcWI3+jY=:fOFLf/IU6dpAi/V5QhDBC3 uiNmBSWUtXLy2V/He517KQ8lYlhIXV7fuXYSOWOG/eu2VqJkGGAvxcWGg6rM4ux/iJGopYw7T KtXelA/aC9O5PBWDmyHMSDsHVKyE6Q8tgjBNrN4EfEHcaXbD00NjM/Jg5VpqzmCI5nQ7gSXBJ 8GV1sltJh5/BqCpl7nHCn9kwQxhjJ7f5v1w7b3ItvQAx1wznj5D0nD6APlUdyW+geTiMjAnT9 r7zsNu6z1l490j+qrSvgw+OWpxc2Dela6ampQWu8vao3M4naqveaGARPPN/lLw24FubzzvAXt S6/TN6Yj+g12N4IlkjnMk/bQRYWIMaEifaxsP5Bx2K40K9m8gxmndezJGDqKoKwOn2qab2r9E sUDNpEVd62SmPBVTR461s4rcEbAn663Z3OCLuy7Jnswh0P4TBI5GMxgYLUhqt9/2EnZrVhaqP Q+mWonMIadbFoCCOEw9PznuZNgbAgrC7Uv50DcEG5fdOLZflMSn5SR9Y7tog744ceDlkKL+kV r4xs73ppoyp74htrTM+uyUgM9GsntjKdIw0kUIg5+e2a4qiZvTqacbjrrz7akqTTKh3f0zP4R RoZ1wIPcx49rbhOseVpvNBMGGg0zRaExPyEx1QaQE8zpV7PDOCtn/MRgBUwajs4QqSXf8Hx1V ALDEDI5n2jSDg1V6bcYs0BkhCFL/1F2N9NYSU1XRPYvMUsxa9QvfyQyywUN59tKOxwp3pTpf5 qdlfYZGGkLzy29uo5vXimbSlllgKzpZDAQH+cPzYMkNMD7/qLswB77Ct5Fw= X-Rspamd-Queue-Id: E47386B82F X-Spamd-Bar: ++++++ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [6.39 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; HAS_REPLYTO(0.00)[freebsd@edvax.de]; MV_CASE(0.50)[]; HAS_ORG_HEADER(0.00)[]; TO_DN_ALL(0.00)[]; MX_GOOD(-0.01)[mx01.schlund.de,mx00.schlund.de]; RCPT_COUNT_TWO(0.00)[2]; FREEMAIL_TO(0.00)[googlemail.com]; RECEIVED_SPAMHAUS_PBL(0.00)[77.229.193.92.zen.spamhaus.org : 127.0.0.10]; RCVD_TLS_LAST(0.00)[]; R_DKIM_NA(0.00)[]; ASN(0.00)[asn:8560, ipnet:217.72.192.0/20, country:DE]; SUBJECT_ENDS_QUESTION(1.00)[]; FROM_EQ_ENVFROM(0.00)[]; ARC_NA(0.00)[]; REPLYTO_EQ_FROM(0.00)[]; FROM_HAS_DN(0.00)[]; NEURAL_SPAM_SHORT(0.95)[0.948,0]; MIME_GOOD(-0.10)[text/plain]; MIME_TRACE(0.00)[0:+]; DMARC_NA(0.00)[edvax.de]; AUTH_NA(1.00)[]; NEURAL_SPAM_MEDIUM(0.71)[0.715,0]; TO_MATCH_ENVRCPT_SOME(0.00)[]; NEURAL_SPAM_LONG(1.00)[0.999,0]; MID_CONTAINS_FROM(1.00)[]; RCVD_IN_DNSWL_NONE(0.00)[75.192.72.217.list.dnswl.org : 127.0.5.0]; R_SPF_NA(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; IP_SCORE(0.34)[ipnet: 217.72.192.0/20(0.10), asn: 8560(1.58), country: DE(-0.01)] X-Spam: Yes X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 31 Mar 2019 06:12:35 -0000 On Sat, 30 Mar 2019 14:54:10 +0000, RW via freebsd-questions wrote: > On Sat, 30 Mar 2019 03:41:14 +0100 > Polytropon wrote: > > > On Fri, 29 Mar 2019 14:01:10 +0000, Steve O'Hara-Smith wrote: > > > > I wouldn't attempt to run an outgoing mail server doing > > > direct MX lookup and delivery these days they anti-spam measures > > > are a nightmare. OTOH reliable delivery relays are not that common > > > either. > > > > Yes, it's not as easy anymore... You have to fight "we know better > > than you!" providers who consider every IP from a dynamic range > > a spammer, > > They pretty much have to. Most spam is caught by simple DNS based > tests which rely on assuming that no dynamic IP addresses sends direct > to MX. In particular most blocklists can't distinguish between a spam > source and a dynamic address, because an infected machine can cause > hundreds of dynamic addresses to be listed. Don't get me wrong - I fully understand that problem. But the attitude of mail operators who seem to consider every provider except themselves a spammer who has to "prove his worth" is annoying. Pwned "Windows" PCs that send tons of spam from their dynamic IP ranges tend to "pollute" whole subnets, so if you accidentally happen to be in the same range (belonging to the same provider or not), whatever you send is considered spam. You can ask to whitelist your IP, but you'll have to do this with almost every mail provider you want to contact, and as soon as you get a new dynamic IP, rinse repeat. Having access to a static IP often helps, but still some of the problems will stay... > These days spammers put a > lot of effort into compromising vulnerable servers, sometimes this > allows their spam to pass SPF, DKIM and even DMARC. Exactly thos emechanisms, intended to _prevent_ spam, can be used by spammers, so mail providers will happily accept their spam because the sender has successfully "proven his worth". If I remember correctly, more than 90% of today's messages transmitted across the Internet is spam, and of course spammers are interested in getting the "big guns" (corporate-class servers), but having access to a distributed network of pwned "Windows" home PCs is still useful for their purposes. > In some cases a home server with an MTA configured to use a smarthost > can be a gift to a spammer if it's compromised. Definitely. That's why securing the server properly and _not_ exposing a public open relay is very important. Due to my impressions and experience, I'd say the common UNIX guy is better at this as any HPC lurking in corporate IT. ;-) -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...