Délai 4 jours réception email

Bonjour,
Je m'envoies certains emails de mon compte Yahoo perso à ma boite mail hébergée chez OVH.
Lors des derniers transferts effectués le 13 janvier, je ne voyais pas ceux-ci arriver. Ils viennent à l'instant d'être délivrés! 4 jours plus tard..

Ci joint l'en-tête de l'email (anonymisé) : on voit bien le délai entre la réception par out0.mail.ovh.net le 13/01 et son transfert vers out24.mail.ovh.net le 17/01...

> Received: from localhost (HELO queue) (127.0.0.1)
> by localhost with SMTP; 17 Jan 2021 18:09:15 +0200
> Received: from unknown (HELO output24.mail.ovh.net) (10.110.115.74)
> by mail265.mgra1.mail.ovh.net with AES256-GCM-SHA384 encrypted SMTP; 17 Jan 2021 18:09:15 +0200
> Received: from out0.mail.ovh.net (unknown [10.101.18.1])
> by out24.mail.ovh.net (Postfix) with ESMTP id 4DJfxR1jWwzCkfJN5
> for ; Sun, 17 Jan 2021 16:09:15 +0000 (UTC)
> Received: from vr31.mail.ovh.net (unknown [10.101.8.31])
> by out0.mail.ovh.net (Postfix) with ESMTP id 4DGC3C1Vccz3rSC
> for ; Wed, 13 Jan 2021 16:05:43 +0000 (UTC)
> Received: from in58.mail.ovh.net (unknown [10.101.4.58])
> by vr31.mail.ovh.net (Postfix) with ESMTP id 4DGC3B6w6nz1QN7wl
> for ; Wed, 13 Jan 2021 16:05:42 +0000 (UTC)
> Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=77.238.178.146; helo=sonic308-18.consmr.mail.ir2.yahoo.com; envelope-from=monemailperso@yahoo.fr; receiver=monemailchez@ovh.com
> Authentication-Results: in58.mail.ovh.net;
> dkim=pass (2048-bit key; unprotected) header.d=yahoo.fr header.i=@yahoo.fr header.b="eOuwrXL0";
> dkim-atps=neutral
> Received: from sonic308-18.consmr.mail.ir2.yahoo.com (sonic308-18.consmr.mail.ir2.yahoo.com [77.238.178.146])
> by in58.mail.ovh.net (Postfix) with ESMTPS id 4DGC3B677czwlZjC
> for ; Wed, 13 Jan 2021 16:05:42 +0000 (UTC)