Product » A free email server for Windows and Linux » Knowledge Base
|Document ID: ||5219|
|Subject: ||What is a dictionary attack|
|Creation date: ||5/31/18 9:55 AM|
|Last modified on: ||7/16/20 11:44 AM|
What is a Dictionary Attack?
A Dictionary Attack occurs when someone tries to send emails to addresses that do not have a
valid account on your system. There are two reasons for someone to perform a dictionary attack against your server.
- Phishing - Often spammers do not know the actual email address of the recipient. In that case, they
try to send messages to a lot of made-up addresses hoping a few will get through.
- Reverse NDR attack - If your SMTP server (either Xeams or a downstream server) is configured to generate NDRs (Non-deliver reports)
you can be made a target of reverse NDR attack.
Check this page for details.
Preventing Dictionary Attack
Xeams automatically detects a dictionary attack and will block an IP address if too many attempts are made to deliver messages to invalid users.
Refer to this page
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