It's just disapointed to see there some issue that not make sense. I tested between my zoho mail and my Outlook account and the mail doesn't goes well when it Zoho Mail account has the sender. But when my zoho was the receiver, it's goes very well. Idk why it's broken like this! If Zoho could contact Microsoft for their troublemaker advanced Office365 spam blocker. This could really help when it's time to indie creators to try contact their customers. 

Domains from Outlook currently active and still affected by the reception issue: hotmail, live, outlook...

There the mail i received from sorta Postmaster system:

This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its recipients. This is a permanent error.

***@hotmail.fr, ERROR CODE :550 - 5.7.1 Unfortunately, messages from [136.143.188.95] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [VI1EUR06FT007.eop-eur06.prod.protection.outlook.com]



Reporting-MTA: dns; mx.zohomail.com
Arrival-Date: Fri, 02 Dec 2022 16:31:48 -0500

Original-Recipient: rfc822; ***@hotmail.fr
Final-Recipient: rfc822; ***@hotmail.fr
Status: 550
Action: failed
Last-Attempt-Date: 2 Dec 2022 21:31:53 GMT
Diagnostic-Code: 5.7.1 Unfortunately, messages from [136.143.188.95] weren't sent. Please contact your Internet service provider since part of their network is on our block list (S3150). You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. [VI1EUR06FT007.eop-eur06.prod.protection.outlook.com]


Received:from mail.zoho.com by mx.zohomail.com
    with SMTP id 1670016708991180.7533425483241; Fri, 2 Dec 2022 13:31:48 -0800 (PST)
Message-ID:<184d4c0b11e.1095ff2c2397371.7066565260151466623@zohomail.com>
Date:Fri, 02 Dec 2022 16:31:48 -0500
From:*** <***@zohomail.com>
To:"***" <***@hotmail.fr>
Subject:=?UTF-8?Q?R=C3=A9=C2=A0:_Hello!?=
Content-Type:multipart/alternative;
    boundary="----=_Part_820841_1633511673.1670016708895"
User-Agent:Zoho Mail