Blocked email

What is blocked email?

You may occasionally receive bounced emails that were never delivered to the recipient. This could happen for a variety of reasons, but sometimes it's due to mail being blocked.

The receiving mail server could view your incoming mail as spam and block it. If that happens you may receive a bounced email with a message explaining that it could not be delivered.

Since it's often difficult to understand why a message is bounced, this article provides a general overview of common issues and how to fix them. If you have any further questions about bounced email please contact support.

Examples of blocked email

Common bounce messages

The bounce message sometimes explains why your email is being blocked, but other times the message can be very vague. It depends on the company bouncing the email back to you. Here are a few examples of the text you may see:

  • 550-Requested action not taken: mailbox unavailable 550-Reject due to policy restrictions.
  • delivery temporarily suspended: host refused to talk to me: 554 Comcast block for spam.


Sometimes mail isn't blocked, but is greylisted instead. If this happens, DreamHost support is unable to assist you with that. Instead, you must wait until the other mail hosts allow email to be received again. Here's an example of a bounce you may see:

  • Message temporarily deferred The user you are trying to contact is receiving mail at a rate that 450-4.2.1 prevents additional messages from being delivered. Please resend your 450-4.2.1 message at a later time.

What can I do about blocked email?

You should contact support if you believe your email is being blocked. You must provide support with the following in order to troubleshoot your issue:

  • full text of the bounce email
  • full headers of the original email (which should be quoted in the bounce). NOTE: These are not the headers of the bounced email.

Contacting Support for Mailblock issues is primarily for reporting purposes. For this reason, you may not receive a response on your issue.

See also

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Article last updated PST.

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