550 You do not have sufficient privileges to send mail

[jerome1g]

When trying to test my x10host email I was able to send email from:
jerome1g@xo3.x10hosting.com to my own personal email.(gmail)
However when I tried to send an email back to jerome1g@xo3.x10hosting.com
I received the following message:

Message not delivered
There was a problem delivering your message to jerome1g@xo3.x10hosting.com. See the technical details below, or try resending in a few minutes.

The response from the remote server was:

550 You do not have sufficient privileges to send mail to this address. Please authenticate and try again.

Final-Recipient: rfc822; jerome1g@xo3.x10hosting.com
Action: failed
Status: 5.0.0
Remote-MTA: dns; xo3.x10hosting.com (198.91.81.3, the server for the domain.)
Diagnostic-Code: smtp; 550-You do not have sufficient privileges to send mail to this address. Please
550 authenticate and try again.
Last-Attempt-Date: Wed, 29 Mar 2017 17:04:48 -0700 (PDT)

Is this a problem I fix or do you guys have to fix it?

 

[lylex10h]

How do you even access the Inbox for that address?

 

[jerome1g]

I login into my cPennel
"https://xo3.x10hosting.com:2083/cpsess2074530780/frontend/x10x3/index.html"
I go to Webmail
I click on the follow "Go to Secure Webmail Login"
I choose Horde as my email
That is where I sent my email from and tried to send email back to

 

[lylex10h]

My diagnosis is that this a special outgoing account only. If I sent a message from that account to kolbysx1@xo7.x10hosting.com it would be delivered. If I sent kolbysx1@xo7.x10hosting.com a message from my @gmail.com it also bounced back.

https://documentation.cpanel.net/display/68Docs/Email+Accounts#EmailAccounts-Defaultemailaccount
This address is also the default From and Reply-to address of outgoing email that your account's PHP scripts send.