Hi, First of all, I would like to apologize for the in- convenience, we have caused for other ISP's. I have to admit, that th communication with the other ISP's was not sufficient. To improve this situation, here again the technical contact for problems regarding our Mailservices:
email: [EMAIL PROTECTED] Fax.: +41 1 277 95 12 To prevenrt further rumoursrumors regarding the cause of the measures we were taking in the last days, here a brief overview of what hapenedhappened in the last days: Starting on Monday 19th, we had a huge amount of traffic due to dictionary attacks. We were fighting with ten to fifteen Million requests for mail addresses, composed of common German first- and second names. A connect started as an ordinary smtp-Session, was sending five to ten rcpt to: sequences, collectingthe responses and did not terminate the Session cleanly. As our Mailsystem was close to break down, we decided to take strong measures against these attacks. First we started with refusing mails from Servers without a reverse entry in the DNS. Although this helped quite a lot, we were still totally overloaded. In this situation, we had to start blocking IP-Ranges to guarantee the mailservice. We tried to block only dynamically assigned IP addresses, to minimize the impact on other users. Unfortunately, this was not always possible to achieve in the speed of blocking IP Ranges required to keep our systems alive. kind regards Robert -- ======================================================== ============== New Tel. number!!! ====================== ======================================================== Robert Meyer Tel.: 01 846 59 45 System Administrator e-mail: [EMAIL PROTECTED] Cablecom GmbH ======================================================== ---------------------------------------------- [EMAIL PROTECTED] Maillist-Archive: http://www.mail-archive.com/swinog%40swinog.ch/
