Mail Delivery Status Notification (Delay)

Mail Delivery Status Notification (Delay)

Hello, I sent an email 2 days ago and I would like to know if it was successfully delivered or not. I'm not sure what to interpret. The email does appear in my "Sent" section and it has a green check mark that says it was delivered. But this message that arrived in my inbox a few minutes later of sending the email still confuses me.  Message I received:

This message was created automatically by mail delivery system.  

THIS IS A WARNING MESSAGE ONLY.  

YOU DO NOT NEED TO RESEND YOUR MESSAGE.  

The original message was received at Fri, 29 Jun 2018 14:47:14 -0700  

----- The following addresses had fatal errors -----  
[Status: Error, Address: <xxxxxx @xxxxx.net>, ResponseCode 421, Host not reachable.]  

Message will be retried for 4 more day(s)  

----- Transcript of session follows -----  

Received:from mail.zoho.com by mx.zohomail.com  
    with SMTP id 1530306089153594.4178730652042; Fri, 29 Jun 2018 14:01:29 -0700 (PDT)  
Message-ID:<1644d59d0bd.125f6cc3c120644 .902949331126845342@dreamlikejewels.com>  
Date:Fri, 29 Jun 2018 16:01:29 -0500  
From:Dreamlike Jewels < info@dreamlikejewels.com>  
User-Agent:Zoho Mail  
To:"\"xxxxx\"" <xxxx @xxxxx.net>  
Subject:Your Order Was Delivered!  
Content-Type:multipart/alternative;  
    boundary="----=_Part_388504_167983847.1530306089150"