From: "Lewis G Rosenthal" Received: from [192.168.100.201] (account lgrosenthal@2rosenthals.com HELO [192.168.100.19]) by 2rosenthals.com (CommuniGate Pro SMTP 5.4.10) with ESMTPSA id 12871090 for ecs-isp@2rosenthals.com; Tue, 22 Apr 2025 16:50:31 -0400 To: eCS-ISP Subject: Trouble getting mail delivered to Office365 (outlook.com), ProofPoint, and Barracuda protected domains Organization: Rosenthal & Rosenthal, LLC Message-ID: <68080114.2090808@2rosenthals.com> Date: Tue, 22 Apr 2025 16:50:29 -0400 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 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Hi, all... For the past few days, I've been dealing with an issue of mail from 2rosenthals.com apparenly getting blackholed by certain providers. We do not receive any kind of DSN. From all accounts, the email is going out for delivery and that's that. However, on the other end, recipients aren't seeing the messages, nor are they getting any kind of spam notification or other warning that a message could not be delivered. Affected domains seem to be hosted with a handful of providers, Office365 among them, which uses outlook.com. Naturally, I've checked both the outlook.com and live.com internal lists, and both show that neither of our IPs is listed. Other MXs which seem to be behaving similarly are: gpphosted.com (ProofPoint) barracudanetworks.com Multiple multiple-RBL checks come up clean for both IPs and our domain. SPF, DKIM, and DMARC configurations all look fine (read: pass specific checks by various third parties, including mxtoolbox.com). Mail flows without incident to gmail.com and yahoo.com. Is anyone else seeing anything like this? TIA -- Lewis ------------------------------------------------------------- Lewis G Rosenthal, CNA, CLP, CLE, CWTS, EA Rosenthal & Rosenthal, LLC www.2rosenthals.com visit my IT blog www.2rosenthals.net/wordpress -------------------------------------------------------------