From: "Lewis G Rosenthal" Received: from [50.73.8.217] (account lgrosenthal@2rosenthals.com HELO [192.168.200.27]) by 2rosenthals.com (CommuniGate Pro SMTP 5.4.10) with ESMTPSA id 12300505 for ecs-isp@2rosenthals.com; Fri, 21 Feb 2025 14:15:15 -0500 Subject: Re: [eCS-ISP] Anyone else seeing issues today with AT&T and RDNS failures when sending? To: eCS ISP Mailing List References: Organization: Rosenthal & Rosenthal, LLC Message-ID: <67B8D0C1.90806@2rosenthals.com> Date: Fri, 21 Feb 2025 14:15:13 -0500 User-Agent: Mozilla/5.0 (OS/2; Warp 4.5; rv:38.0) Gecko/20100101 Firefox/38.0 SeaMonkey/2.35 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi... On 02/20/25 05:11 pm, Steven Levine wrote: > In , on 02/20/25 > at 03:35 PM, "Lewis G Rosenthal" said: > > Hi there, > >> Today, att.net rejected mail from us to one of their subscribers with a >> 550 5.7.1 error: >> >> host ff-ip4-mx-vip1.prodigy.net [144.160.159.21] >> SMTP error from remote mail server after MAIL FROM:> 2rosenthals.com domain>: >> 550 5.7.1 Connections not accepted from servers without a valid >> sender domain.flph829 Fix reverse DNS for 50.73.8.217 >> secmgr-va.2rosenthals.com > I get the same here > > ; <<>> DiG 9.11.37 <<>> -x 50.73.8.217 > ;; global options: +cmd > ;; Got answer: > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 42869 > ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1 > > ;; OPT PSEUDOSECTION: > ; EDNS: version: 0, flags:; udp: 512 > ;; QUESTION SECTION: > ;217.8.73.50.in-addr.arpa. IN PTR > > ;; ANSWER SECTION: > 217.8.73.50.in-addr.arpa. 3600 IN PTR secmgr-va.2rosenthals.com. > > ;; Query time: 246 msec > ;; SERVER: 8.8.8.8#53(8.8.8.8) > ;; WHEN: Thu Feb 20 14:12:39 PST 2025 > ;; MSG SIZE rcvd: 92 > > A wed search for > > "flph829" > > results in a few hints that match your problem, but nothing recent. > Yeah, whatever it was (likely that particular server), a subsequent retry got the message through. Very odd, though. IAC, it was a good opportunity for me to just check to ensure that RDNS was indeed correct, because I never really look. Thanks, and apologies, all, for the noise. -- Lewis ------------------------------------------------------------- Lewis G Rosenthal, CNA, CLP, CLE, CWTS, EA Rosenthal & Rosenthal, LLC www.2rosenthals.com visit my IT blog www.2rosenthals.net/wordpress -------------------------------------------------------------