The original message was received at Mon, 20 Nov 2023 17:12:34 -0500 from m0338037.ppops.net [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <andres_gomez@hks.harvard.edu> (reason: 554 5.4.14 Hop count exceeded - possible mail loop ATTR34 [CY4PEPF0000FCC5.namprd03.prod.outlook.com 2023-11-20T22:12:35.047Z 08DBE75982FC1848]) ----- 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 [CY4PEPF0000FCC5.namprd03.prod.outlook.com 2023-11-20T22:12:35.047Z 08DBE75982FC1848] 554 5.0.0 Service unavailable