Can not receive mails

Can not receive mails

Hi,

I tried to send a mail to my zoho mail, and I got below error:

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 Wed, 25 Dec 2019 06:45:33 -0800
from XXXXXXXX@ettigah.com [XXXXXXX@ettigah.com]

----- The following addresses had fatal errors -----
[Status: Error, Address: <XXXXXXXX@ettigah.com>, ResponseCode 421, Host not reachable.]

Message will be retried for 4 more day(s)

Reporting-MTA: dns; mx.zohomail.com
Arrival-Date: Wed, 25 Dec 2019 17:00:07 +0300
Original-Recipient: rfc822; <XXXXX@ettigah.com>
Final-Recipient: rfc822; XXXXXXXX@ettigah.com
Status: 421
Action: failed
Last-Attempt-Date: 25 Dec 2019 14:45:33 GMT
Diagnostic-Code:
----- Transcript of session follows -----

Received:from mail.zoho.com by mx.zohomail.com
    with SMTP id 1577282407053547.8067906612716; Wed, 25 Dec 2019 06:00:07 -0800 (PST)
Message-ID:<16f3d5b8a87.f64688c633909.XXXXXXXXXXXX@ettigah.com>
Date:Wed, 25 Dec 2019 17:00:07 +0300
From:XXXXX <XXXXXX@ettigah.com>
User-Agent:Zoho Mail
To:<XXXXXX@ettigah.com>
Subject:test mail
Content-Type:multipart/alternative;
    boundary="----=_Part_76442_1022462355.1577282407047"

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

In addition to that, if I tried to send mail to (hotmail) for example, it goes to (Junk) mail not to inbox.

So please help