You can block networks or single computers within the control access menu under the SMTP settings (second tab). For instance, if you are seeing dictionary attacks from a 207.50.45.X ip and a 207.50.33.X you might try entering a class B group of 207.50.0.0 255.255.0.0 to block any addresses within the first two octets of 207.50.X.X.
If they are coming from many networks not associated with a single Class B, go through and block the class C's such as 207.50.45.0 255.255.255.0, so on and so forth. This is the main reason I now employ IMGate to eliminate dictionary attacks from harvesters. Using RBLs is really the only true longterm fix for this problem. ---------- Original Message ---------------------------------- From: "for imail listserv " <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] Date: Thu, 13 Jun 2002 08:55:30 -0500 Can not block since they are changing every 5-10 minutes. Where can I find a blocker? ---------- Original Message ---------------------------------- From: "Jason Newland" <[EMAIL PROTECTED]> Reply-To: [EMAIL PROTECTED] Date: Thu, 13 Jun 2002 08:38:58 -0500 >Try blocking the IPs at your border router. Else, purchase a Blocker that >prevents Dictionary attacks. > > > >Jason > >----- Original Message ----- >From: "for imail listserv " <[EMAIL PROTECTED]> >To: <[EMAIL PROTECTED]> >Sent: Thursday, June 13, 2002 8:14 AM >Subject: [IMail Forum] bruteforce attack > > >> We are under a bruteforce dictionary attack. Has been going on >> for the last 24 hours. >> >> They are pretty good since they change ip address for every >> connection and only try 25 email addresses. >> >> We are not using SMTP Authentication yet but it is the plans for >> the next 2 weeks or so. >> >> Any idea on how to stop this. >> >> H. >> >> ________________________________________________________________ >> Sent via the WebMail system at i360.net >> >> >> >> >> >> Please visit http://www.ipswitch.com/support/mailing-lists.html >> to be removed from this list. >> >> An Archive of this list is available at: >> http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ >> >> Please visit the Knowledge Base for answers to frequently asked >> questions: http://www.ipswitch.com/support/IMail/ >> > > >Please visit http://www.ipswitch.com/support/mailing-lists.html >to be removed from this list. > >An Archive of this list is available at: >http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > >Please visit the Knowledge Base for answers to frequently asked >questions: http://www.ipswitch.com/support/IMail/ > ________________________________________________________________ Sent via the WebMail system at i360.net Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/ -- -- Mind Information Systems LLC Technical Support Staff Jonathan Ingram Phone: (559)730-3600 Web: <http://www.mindinfo.com/tech_support/> -- -- Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Please visit the Knowledge Base for answers to frequently asked questions: http://www.ipswitch.com/support/IMail/
