Error when sending and receiving emails

Why has your email been blocked by our spam and virus blocker?

Unfortunately, spam and virus emails are causing considerable economic damage. That’s why an effective virus protection has become indispensable. The Hornetsecurity filter systems guarantee a spam recognition rate of 99.9 &. However, in extremely rare occasions, emails are being blocked that should have been delivered to the recipients. In case you’ve received an error notification while sending an email, we regret to have accidentally blocked your message.

By visiting this site, the blocked IP address was automatically added to a reputation list. Updating the system usually takes about 15 minutes. After that, you should be able to send or deliver it via your mail server. If your email address is still blocked, please fill out this form to unblock it.

If, however, further problems still occur during delivery, you will find further information and tips below.


Further information and tips below


450 4.1.8 Sender address Rejected

The sender domain hasn’t got a valid DNS A or MX record. Please contact your administrator.

450 4.1.8 Recipient address rejected

The recipient email system of the customer cannot process any requests now, please try later again.

450 4.5.7 Loop detected

The email is running in a loop. Please contact the administrator of your system so that they can contact us.

450 5.5.5 EMail deferred because of Spam sending

You have been temporarily been blocked because of spam sending. Please contact us.

550 Requested action not taken: mailbox unavailable

The recipient you’ve tried to reach does not exist in our system or the recipient hasn’t used their mailbox for quite a long time and it’s been temporarily deactivated due to inactivity. Please check the spelling of the email address.

554 5.6.9 Customer Reject

The customer has added a rule that blocks the reception of the email. Please contact the customer so that they can contact us if needed.

554 5.5.4. No SMTP service – IP address is black listed

To reduce inbound spam emails, IP addresses that distribute spam emails are being filtered. One or more IP addresses within your IP range has been identified as a potential spam sending distributor. Therefore, these emails are being rejected to protect the infrastructure of our customers. If you have used the URL from the NDR (Bounce Message) to open this landing page, your IP address has been added to a temporarily whitelist automatically.

The update takes approximately 15 minutes. Immediately afterwards, the email server can be used again to send data into Hornetsecurity systems (as usual). If you still encounter problems, please follow this link.

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