I'm using name.com server. Recently I created some webmail's from cPanel Email Accounts. But sending mail from my email to other email is working but my mails not receiving mail from other mail services. I think this problem related with DNS. But I'm not sure. Ex. are below after sent mail from other mail to my webmail.
Gmail Receipt
Mail Delivery Subsystem <https://mailer-daemon@googlemail.com>
Address did not find Your message wasn't delivered to <https://name@ex.institute>
because the address couldn't be found or is unable to receive mail.
The response from the remote server was: 554 5.1.1
<https://name@ex.institute>: Recipient address rejected: User unknown
Zoho Receipt
Undelivered Mail Returned to Sender
This message was created automatically by mail delivery software. A
message that you sent could not be delivered to one or more of its
recipients. This is a permanent error.
<https://name@ex.institute>, ERROR CODE :554 - 5.2.1 Too many failures for the
recipient
Reporting-MTA: dns; <https://mx.zohomail.com> Arrival-Date: Thu, 11 Aug 2022
12:05:07 +0600
Original-Recipient: rfc822; <https://name@ex.institute> Final-Recipient: rfc822.
<https://name@ex.institute> Status: 554 Action: failed Last-Attempt-Date: 11 Aug
2022 06:05:08 GMT Diagnostic-Code: 5.2.1 Too many failures for the
recipient
Received:from <https://mail.zoho.com> by <https://mx.zohomail.com>
with SMTP id 1660197907519284.79215051355425; Wed, 10 Aug 2022 23:05:07 -0700 (PDT)
Message-ID:<https://1828b81ac27.db15426d1019735.8496477914736660465@example.com>
Date:Thu, 11 Aug 2022 12:05:07 +0600 From:Support
<https://fromname@example.com> To:"zaman" <https://name@ex.institute> Subject:Re: Fwd:
Test Content-Type:multipart/alternative.
boundary="----=_Part_3289286_810121335.1660197907495" User-Agent:Zoho Mail
Make sure that you have the correct MX records set for your domain name. If necessary, ask your hosting provider to check if everything is okay with your domain name, as well as with the mail service on the server where your account is being hosted. If they lack support, then I would recommend looking for a managed hosting provider that can help you in such situations.