ARC-Authentication-Results: i=1; mx.google.com;
spf=neutral (google.com: 62.161.4.28 is neither permitted nor denied by best guess record for domain of EXPEDITEUR TIERS@TIERS) smtp.mailfrom=EXPEDITEUR TIERS@TIERS
spf est en "neutral" sur cette adresse ( Orange devrait y jeter un oeil ) // serveur(s) mail Orange
Received: from [43.252.233.249] ([43.252.233.240]) (authenticated) by smtp28.msg.oleane.net (MSA) with ESMTP id 08N53OAm021919 for <NOUS@NOUS>; Wed, 23 Sep 2020 07:03:32 +0200
L'adresse ayant envoyé le message (43.252.233.240)
X-Backend: vm-smtp-sophos-mta61
X-PFSI-Info: PMX 6.4.9.2830568, Antispam-Engine: 2.7.2.2107409, Antispam-Data: 2020.9.23.45417, AntiVirus-Engine: 5.77.0, AntiVirus-Data: 2020.9.13.5770003 (Mal/DocDl-K)
[b]X-PMX-VirusScan: INFECTED (Mal/DocDl-K)[/b]
X-PMX-Backend: PMX 6.4.9.2830568, Antispam-Engine: 2.7.2.2107409, Antispam-Data: 2020.9.23.45417, AntiVirus-Engine: 5.77.0, AntiVirus-Data: 2020.9.13.5770003 running on vm-smtp-sophos-mta61
L'antivirus semble être Sophos
Bref, Gmail avec le SPF Neutral a relayé le message, d'ou l’intérêt d'utiliser DMARC DKIM et SPF correctement.