Dictionary Attack Response – Problem Sending Mail

If you receive a response of “Connection denied after dictionary attack“, it could be the result of a couple of factors relating to the systems used in preventing spam and spam attacks on the server. One possible source could be that you don’t have the “my server requires authentication” setting for your outgoing mail server (Note: different mail programs have different names for this). In such a case, if you haven’t attempted to receive mail in the previous 30 minutes, you have likely attempted to send and failed several times, and this eventually caused you to get your IP address blocked by the system.

To correct this issue, please perform the following steps:

  1. Check the “my server requires authentication” in your email client (such as Outlook, Mac Mail, Thunderbird, etc.).
  2. Click here to find out what your IP address is.

Then use the ticket portal in AMP to submit a ticket letting them know your IP address and that you have been blocked for dictionary attack and need to be cleared to send mail from the server again.

Support will then clear the IP and notify you that you are cleared to send.

The second primary source is that you may have sent more than the required number of false addresses to be designated a dictionary attack. This is rare, but it can happen if you have an email address misspelled and try multiple times. We don’t publish the number of failed attempts necessary to generate the dictionary response for security reasons, but if you receive the dictionary attack response and already have outgoing authentication checked, you will need to follow from step 2 above to get this cleared. Support will check to see what the cause of your listing was and get back to you.

Carrie Smaha
Carrie Smaha Senior Manager Marketing Operations

Carrie enjoys working on demand generation and product marketing projects that tap into multi-touch campaign design, technical SEO, content marketing, software design, and business operations.

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