Email Bounced Back

This is a list of the most common email bounce-back messages.

Mailbox is Full

From: Mail Delivery System <Mailer-Daemon@host.irsinternet.com>
Date: Mon, Nov 5, 2018 at 9:03 PM
Subject: Mail delivery failed: returning message to sender
To: <someemail@gmail.com>

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. The following address(es) failed:

name@domainname.com
LMTP error after end of data: 452 4.2.2 <name@domainname.com> Mailbox is full / Blocks limit exceeded / Inode limit exceeded:
retry timeout exceeded

Messages similar to this error are stating that the recipient email account is full. The recipient needs to delete email out of their mailbox to free up space so they can receive and send additional email. The error may also say "Mail quota exceeded."

Address Not Found

The email account that you tried to reach does not exist. Please try double-checking the recipient's email address for typos or unnecessary spaces. Learn more at https://support.google.com/mail/?p=NoSuchUser n44sor22217424ote.155 - gsmtp

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

email@email.com
host mx01.mail.com [74.208.5.22]
SMTP error from remote mail server after RCPT TO:<email@email.com>:
550 Requested action not taken: mailbox unavailable

Messages similar to this error are stating that the recipient email account does not exist. Check for typos in the email address, otherwise the email account has not been created.

More common errors can be found here: https://www.siteground.com/kb/common-email-bounce-back-errors/