Date: Mon, 21 Jan 2019 10:30:25 +0300 From: Odhiambo Washington <odhiambo@gmail.com> To: Patrick Mahan <plmahan@gmail.com> Cc: User Questions <freebsd-questions@freebsd.org> Subject: Re: Trying to understand some email issues Message-ID: <CAAdA2WPGE5793RMdpeo_r_js2mLgT5zV0gQTRBxfReCBJdPrTw@mail.gmail.com> In-Reply-To: <CAFDHx1JFWH8FAJ3nbvZC3m6CCpbjCqrG01PYNMOHJSKo2HnWWQ@mail.gmail.com> References: <CAFDHx1JFWH8FAJ3nbvZC3m6CCpbjCqrG01PYNMOHJSKo2HnWWQ@mail.gmail.com>
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On Mon, 21 Jan 2019 at 09:35, Patrick Mahan <plmahan@gmail.com> wrote: > All, > > FreeBSD 11.2 > > Running postfix 3.3.2_1,1 > > I'm getting hammered with thousands of emails from yahoo.com - > > Here is an example - > > Jan 20 22:09:01 ns postfix/smtp[1308]: 2DA97A2E2EF: to=<pwascak@aol.com>, > relay=mx-aol.mail.gm0.yahoodns.net[98.137.157.43]:25, delay=13730, > delays=13728/0.31/1.1/0.06, dsn=4.7.0, status=deferred (host > mx-aol.mail.gm0.yahoodns.net[98.137.157.43] said: 421 4.7.0 [TSS04] > Messages from 23.24.207.145 temporarily deferred due to user complaints - > 4.16.55.1; see https://help.yahoo.com/kb/postmaster/SLN3434.html (in reply > to MAIL FROM command)) > > I'm trying to determine if I am somehow relaying emails to yahoo.com, or > is > this someone attacking me. > Your server's public IP address is 23.24.207.145, right? Yahoo MX is "temporarily" (that is what SMTP Error Code 451 is. Code 550 is "permanently") rejecting mail from your server. This is normal with Yahoo and you need to go to the given URL to understand why and possible ways of mitigating the issue. The thing is that ultimately, after some retries, Yahoo servers may accept the mail. You need to check your Postfix logs for this particular, or other such emails to see if they are originated by your legit users/IPs. > I am pretty sure I have postfix to avoid acting like a relay for > unauthenticated connections. But this maybe something I have messed up. > This has been happening only since I upgraded to 11.2 (I was at 9.x). I > also just recently switch from sendmail to postfix as well. > You just need to sit down and read Postfix documentation and understand it's internals, especially the logs. Without a clear understanding of the logs, you should be very worried as a Mail SysAdmin, very worried! :-) I am NOT a Postfix Admin, but I understand some stuff about it. I use Exim as my preferred MTA. > I can provide my postfix config on request if needed. > Not necessary for this case. However, I would advise you to sit easy if you followed a proper howto in setting up your MTA. Just take your time now to read about and understand the logging. > > Pointers to other mail-lists are welcomed. I decided to start here before > jumping on the postfix mailing list. > > No problem. -- Best regards, Odhiambo WASHINGTON, Nairobi,KE +254 7 3200 0004/+254 7 2274 3223 "Oh, the cruft.", grep ^[^#] :-)
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