Hello.

I'm having problems sending e-mails to my shipping company.

user@shippingcompanydomain.com INVALID_ADDRESS, ERROR_CODE :550, ERROR_CODE :5.1.1 <user@shippingcompanydomain.com>: Recipient address rejected: User unknown in virtual mailbox table 

Reporting-MTA: dns; mx.zohomail.com
Arrival-Date: Tue, 5 Nov 2019 05:54:18 -0800 (PST)
Original-Recipient: rfc822; user@shippingcompanydomain.com
Final-Recipient: rfc822; user@shippingcompanydomain.com
Status: 550
Action: failed
Last-Attempt-Date: 5 Nov 2019 13:54:22 GMT
Diagnostic-Code: user@shippingcompanydomain.com INVALID_ADDRESS, ERROR_CODE :550, ERROR_CODE :5.1.1 <user@shippingcompanydomain.com>: Recipient address rejected: User unknown in virtual mailbox table



Received:from localhost (191.253.96.66 [191.253.96.66]) by mx.zohomail.com
    with SMTPS id 1572962058039910.1982393914936; Tue, 5 Nov 2019 05:54:18 -0800 (PST)
Message-ID:<1364135401.575.1572962057409.JavaMail.root@systextil>
Date:Tue, 5 Nov 2019 05:54:18 -0800 (PST)
From:user@mycompanydomain.com

To:user@shippingcompanydomain.com
Subject:Envio automatico da NF-e 3924/1
Content-Type:multipart/mixed;
    boundary="----=_Part_574_229655546.1572962055091"

Can somebody help me, please?

Thank you very much,

Cicero