550 Error : Dictionary Attack

Dictionary Attack
A method often used by spammers. They send various emails or passwords to a domain hoping that one will succeed.

The server detects a dictionary attack when a user attempts to send email to four consecutive invalid email addresses. When this happens the server believes it is getting spammed by someone who is trying a bunch of addresses to see if any of them get through.

The dictionary attack block will be removed after 1 hour if there are no more than 4 erroneous emails in a row.

You must stop sending emails and pause your mailing lists. Then wait approximately 1 hour, and it should clear itself.

If you were using Outlook, during the wait you can try using webmail to send messages.

  • Email, SSL
  • 12000 Users Found This Useful
Was this answer helpful?

Related Articles

535 Incorrect authentication data

If you have a Linux dedicated server, you can fix this problem. In root WHM, go to Email >...

Are you able to receive emails but not send?

If you aren't able to send this usually means one thing... your internet provider is blocking you...

Are you able to send emails but not receive?

Either your domain is over quota, or your e-mail address itself is over quota. You will need to...


Box Trapper returns a confirmation email to senders, who must reply before their email is...

Can I get a copy of my Email Logs?

We can provide your email logs per domain name. Please contact HDWEBPROVIDER™ via phone, live...