23 via Frontend Transport Thu, 07:07:36 +0000 X-IncomingTopHeaderMarker:Īuthentication-Results: spf=temperror (sender IP is 23.251.230.203) smtp.mailfrom=domainname dkim=pass (signature was verified) header.d= domainname dmarc=pass action=none om= domainname compauth=pass reason=100 Received-SPF: TempError (: error in processing during lookup of domainname DNS Timeout) Received: from (23.251.230.203) by .com (10.13.178.215) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id. AUĪuthentication-Results: spf=temperror (sender IP is 180.189.28.115) smtp.mailfrom=domainname dkim=pass (signature was verified) header.d= domainname dmarc=pass action=none om= domainname compauth=pass reason=100 Received-SPF: TempError (: error in processing during lookup of domainname DNS Timeout) Received: from (180.189.28.115) by .com (10.152.67.233) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id. Having spoken with AWS regarding this issue (I initially thought the issue was isolated to domains hosted in Route53, they concur that the issue lies solely with the receiving mail platform being /) At a guess I would say Microsoft is intermittently having an issue performing DNS lookups of TLD's ending in. How does one make Microsoft aware of a fairly significant and widespread issue affecting multiple end users? I have not been able to make any other TLD fail as of yet. This is a huge issue, not only for us, but for anyone sending mail to Hotmail from an. I have obfuscated the domain name for privacy reasons. I have posted a portion of the email headers received in hotmail, being sent via multiple platforms, servers, subnets which have all failed. I have tested a single email with multiple recipients to platforms such as Gmail, Yahoo and Hotmail in which Hotmail is the only recipient which reports an SPF TempError, DNS Timeout. I have tested this across multiple Mail platforms such as Amazon accounts (SES), G Suite for business web interface, an internal SMTP relay which outbounds via Proofpoint and also from an O365 tenant. I have since managed to replicate the issue across >5 different domains ending in. AU Domains.ĭuring the past few days, I have performed extensive testing to validate the issue which initially I thought was isolated to a single one of our. I have encountered an issue I believe is extremely widespread (albeit intermittent) affecting deliverability to / from.