Recently outgoing emails from our project (“confluence”) have been failing, apparently due to some service “mail.protection.outlook.com” that your SMTP server uses. Here’s an example:
Diagnostic information for administrators:
Generating server: its-msxhybrid5.ad.unc.edu
nein2000@web.de
CY4PEPF0000EE33.mail.protection.outlook.com
Remote Server returned ‘550 5.7.64 TenantAttribution; Relay Access Denied [CY4PEPF0000EE33.namprd05.prod.outlook.com 2024-01-14T16:51:49.114Z 08DC14C082F6C312]’
Original message headers:
Received: from relay.unc.edu (152.2.26.163) by its-msxhybrid5.ad.unc.edu (152.2.79.87) with Microsoft SMTP Server id 15.2.1118.40; Sun, 14 Jan 2024 11:51:48 -0500 Received: from vhost-confluence1.int.ibiblio.org ([152.19.134.38]) by relay.unc.edu with Microsoft SMTPSVC(10.0.17763.1697); Sun, 14 Jan 2024 11:51:48 -0500 Received: by vhost-confluence1.int.ibiblio.org (Postfix, from userid 48) id 2A43A20031B; Sun, 14 Jan 2024 11:51:48 -0500 (EST) To: <nein2000@web.de> Subject: 46N 28E submitted From: Rainer Mautz <rainer@mautz.net> Reply-To: <rainer@mautz.net> X-Sender: <rainer@mautz.net> X-Mailer: PHP/7.3.31-1~deb10u5 X-Priority: 3 MIME-Version: 1.0 Content-Type: text/plain; charset=“ISO-8859-1” Content-Transfer-Encoding: 8bit Message-ID: <20240114165148.2A43A20031B@vhost-confluence1.int.ibiblio.org> Date: Sun, 14 Jan 2024 11:51:48 -0500 Return-Path: rainer@mautz.net X-OriginalArrivalTime: 14 Jan 2024 16:51:48.0217 (UTC) FILETIME=[F6D34690:01DA4709]
Please look into why you are using “mail.protection.outlook.com”, and why this is now rejecting outgoing emails