The original message was received at Fri, 16 Feb 2024 04:20:44 -0500 from m0338033.ppops.net [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <Sultan_Orazbayev@hks.harvard.edu> (reason: 554 5.4.14 Hop count exceeded - possible mail loop ATTR34 [SA2PEPF000015CB.namprd03.prod.outlook.com 2024-02-16T09:20:45.005Z 08DC2C3E65F78D55]) ----- Transcript of session follows ----- ... while talking to hu.mail.protection.outlook.com.:

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DATA <<< 554 5.4.14 Hop count exceeded - possible mail loop ATTR34 [SA2PEPF000015CB.namprd03.prod.outlook.com 2024-02-16T09:20:45.005Z 08DC2C3E65F78D55] 554 5.0.0 Service unavailable