Cannot send email to live.com address from Outlook

Cannot send email to live.com address from Outlook

Sent a test message from Outlook and got the following bounce back message. Sent a second test directly from the Zoho mail app on my phone - the message was sent and received. 

----------------------------------------------------------------------------------------------------------------------------------------

From: System Administrator
Sent: Thursday, March 11, 2021 3:58 AM
To: Michelle Wallace
Subject: Undeliverable: WTF

Your message did not reach some or all of the intended recipients.

Subject:     WTF

Sent:  3/11/2021 3:58 AM

The following recipient(s) cannot be reached:

      dar***********rs@live.com on 3/11/2021 3:58 AM

            None of your email accounts could send to this recipient.

----------------------------------------------------------------------------------------------------------------------------------------

Can you please resolve this issue? It should not matter which email client I use. If I can send successfully to the recipient from native Zoho apps I should be able to do so from other email clients.