Help Center

Fixing the 450 4.7.1 [TCR] error or 550 4.7.1 [TCR] error

If you are receiving this error, receiving mail systems are frequently rejecting your email messages. Receiving systems typically reject messages when they determine that the content is offensive, malicious, or spam-like. If your account is somehow compromised by a spammer, this error message helps slow down the rate of sending and abusive behavior, even when our own content filter has not yet determined that your account is under an other's control.

What can I do to unblock my account?

Our system will stop generating this error message when email recipients stop rejecting the content of your email messages. Here are some steps you can take to clean up the email coming from your account:

    1. Secure your account against compromise by spammers:
      • Change your password. Ensure your new password has a minimum length of eight characters and uses a mixture of upper and lower case letters, numbers, and special characters.
      • Verify that your operating system is running with the latest security updates.
      • Update your anti-virus software and conduct a full scan of your system to ensure that a spammer has not installed spam-sending malware on your computer.
    2. If you have recently sent a newsletter or other type of mass mailing from your account, verify that none of the URLs within your messages have been flagged by anti-spam systems. Use the Trusted Source URL check to check a URL or domain's reputation. Generally speaking, make sure you are following best practices when sending a bulk campaign, such as using an opt-in only mailing list.
    3. Contact receivers and ask them to Safelist your message content. Large receivers like Gmail and AOL are unlikely to honor requests like this; however, smaller receivers may be open to assisting you in this manner. Receivers each have their own policies and thresholds for message exemptions and abuse.

Please note that email receivers are free to reject your email messages for any reason. The decision to reject your email is not under our control.

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