I send a newsletter to people that subscribe to it. I use my website's server to send the e-mail (from e-mail management software called Interspire), and it uses my e-mail address' SMTP information to send it. A large percentage of the e-mails return with SMTP error 550, mostly from orange.fr, wanadoo.fr, sfr.fr and Hotmail.

I can't figure out what error 550 is supposed to mean. It just says that the message is rejected.

Here is a sample response (with some e-mail addresses removed):

De: Mail Delivery System 

Objet: Mail delivery failed: returning message to sender

Date: 5 août 2015 19:27:05 UTC−4

À: [email protected]

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:

  [email protected]
    host smtp-in.orange.fr []
    SMTP error from remote mail server after end of data:
    550 5.2.0 Mail rejete. Mail rejected. ofr_506 [506]

------ This is a copy of the message, including all the headers. ------

Received: from cloud100.whc.ca ([]:43757 helo=www.myserver.com)
    by cloud100.whc.ca with esmtpa (Exim 4.85)
    (envelope-from )
    id 1ZN7ay-00031C-Lc
    for [email protected]; Thu, 06 Aug 2015 00:55:36 +0200
  • Check mxtoolbox.com/blacklists.aspx for both your domain name and IP address. If you use a mail service, then you will need to test their domain name and IP addresses. It is likely that an anti-spam filter is being triggered. Some e-mail systems reject with a 550 automatically from blacklisted domains and IPs whereas some accept the e-mail and mark it as spam.
    – closetnoc
    Aug 13, 2015 at 17:55

1 Answer 1


Most likely because the people providing you email addresses have given you a bogus email, typed it wrong, they have deleted their account or the account is suspended. 550 error is related to mail not being able to received and not related to spam.

Unless you have a 'confirm' email input field on your signup to email subscription then its likely mistypes and you should expect these to occur often.

Error 550

Simply put, a 550 error code means that your SMTP server isn't able to deliver the sent email to the user because his mailbox does not exist: either the customer has entered it wrong (a typical example is something like [email protected] instead of [email protected]), or the account has been deactivated and replaced with a new one (but you didn't know it).

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