Am Thu, 25 Sep 2025 09:28:22 +0100 schrieb Laura Atkins <[email protected]>:
> This has nothing to do with SPF. This article > (https://www.mimecast.com/threat-intelligence-hub/microsoft-direct-send-abuse/) > may help explain why Direct Send is a problem for O365 to O365 sends. > Specifically: The article above relates to email relayed via o365, not received directly from 3rd party emails provider like us if I got that right. > Specifically: direct send is unauthenticated email that looks exactly like > authenticated email when sending from O365 to O365 users. He’s not actively > sending the mail over your infrastructure if the messages are blocked using > Direct Send. So I don't understand whats causing this issue. This is the error generated on our platform with envelope sender sender@senderdomain recipientdomain and senderdomain are two different domains - both on Outlook 365 - probably both have DirectSend set to disabled. SPF record of senderdomain allows our ip range to use that domain as envelope sender, this is our customer sending invoices via email. ----- The following addresses had permanent fatal errors ----- <recipient@recipientdomain> (reason: 550 5.7.68 TenantInboundAttribution; Direct Send not allowed for this organization from unauthorized sources. [ZRH2EPF00000150.CHEP278.PROD.OUTLOOK.COM 2025-09-17T12:40:14.733Z 08DDF441EEC97DA5]) ----- Transcript of session follows ----- ... while talking to recipientdomain.mail.protection.outlook.com.: >>> DATA <<< 550 5.7.68 TenantInboundAttribution; Direct Send not allowed for this organization from unauthorized sources. [ZRH2EPF00000150.CHEP278.PROD.OUTLOOK.COM 2025-09-17T12:40:14.733Z 08DDF441EEC97DA5] 550 5.1.1 <recipient@recipientdomain>... User unknown <<< 503 5.5.2 Need rcpt command [ZRH2EPF00000150.CHEP278.PROD.OUTLOOK.COM 2025-09-17T12:40:14.733Z 08DDF441EEC97DA5] Mit freundlichen Grüssen -Benoît Panizzon- -- I m p r o W a r e A G - Leiter Commerce Kunden ______________________________________________________ Zurlindenstrasse 29 Tel +41 61 826 93 00 CH-4133 Pratteln Fax +41 61 826 93 01 Schweiz Web http://www.imp.ch ______________________________________________________ _______________________________________________ mailop mailing list [email protected] https://list.mailop.org/listinfo/mailop
