Mail Bounce 553 error code Mail delivery failed: returning message to sender

            September 25, 2019

Why am i getting the following error "SMTP error from remote mail server after RCPT 553 "RCPT TO" mailbox unavailable "

So when a email bounces, it can really bother and times its very frustrating, its good to know why your email bounces. Why wait for the Support tickets to be answered when the answer is going to be same.

As part of our support service, we are always here to provide you help and resolve your issue. If you further have any questions you can always open a new support ticket with your concern.

Common variations of the 553 email error

  • 553 5.7.1 Not an open relay, so get lost
  • 553 Invalid user.
  • 553 message blocked, you are not authorized to send mail, authentication is required.
  • 553 Null Sender is not allowed.
  • 553 5.1.1 sorry, no mailbox here by that name.
  • 553 #5.1.8 Domain of sender address does not exist
  • 553 5.3.0 … Address does not exist
  • 553 5.3.0 … No such user
  • 553 5.3.0 … No such user here
  • 553 5.3.0 … User unknown, not local address
  • 553-Message filtered. Please see the FAQs section on spamn
  • 553 does not have a mailbox here
  • 553 does not accept mail sent to
  • 553 sorry, no mail-box here by that name. (#5.1.1)
  • 553 sorry, no mailbox here by that name (#5.1.1)
  • 553 sorry, rcpt user invalid (#5.7.1)
  • 553 sorry, that domain isn’t in my list of allowed rcpthosts
  • 553 sorry, that domain isn’t in my list of allowed rcpthosts (#5.7.1)
  • 553 sorry, the recipient in not a valid user on this domain (#5.7.1)
  • 553 sorry, this recipient doesn’t exist.
  • 553 sorry, this recipient is not in my validrcptto list (#5.7.1)
  • 553 sorry, your envelope sender is in my badmailfrom list (#5.7.1)
  • 553 Your email address is denied.

A 553 email error is normally related to SMTP authentication not being used. Most mail servers require that you authenticate with a valid user on that system, before youre allowed to relay a remote message out. However some mail administrators will also using the 553 error if a user doesnt exist or for various other reasons as well.

What is the error SMTP error from remote mail server after RCPT TO?

This error message is a very confusing one, as it can be triggered due to a number of causes. But usually the bounce message that arrives contains the details about the error.

The RCPT command is used to tell the sender mail server, who the recipient of your message is. The error message denotes that the sending mail server faced an error during that command, while trying to send mails.

So in this case the ERROR Denotes that the following

1) The user may be blacklisted on the server where you are trying to send.

2) The user may be temporarily be suspended or deactivated.

3) The Mail server you are trying to send has an error or is having trouble.

4) The mailbox has been removed, deleted etc.

The best thing is to try to contact the email id from an alternate route or via different media like SMS/ Phone call etc and inform them about this.


SMTP error from remote mail server after RCPT TO error is a common error that affects email delivery. Here weve discussed four major causes our Server Support Engineers have seen and how we fix it."