Monday, March 26, 2007

Spam, spam, spam and spam

A stupid glitch in a Microsoft wizard has left me with major headaches with our smtp server. So please skip over if you are not interested while I slip into geek mode.

What the Small Business Server 2003 Internet connection wizard did was reset the permissions on relaying via our smtp (simple mail transfer protocol) server. Our server became an open relay. It is generally how spam email senders operate. They cannot generate large numbers of emails off of there own Internet Service provider so they look for insecure smtp servers and use them to send their spam. The internet connection wizard set out smtp server to allow connections from users with accounts on the server and from the servers own IP address. What seemed to be happening is that mail being relayed seemed to be hitting the server before being relayed and therefore when the emails got to be relayed they came from the server IP address and were therefore allowed. 750,000 emails were generated off our server in 3 days using this method. Thankfully our spam protection caught them all. Our server is now set to only relay email from authorised and authenticated users.

What a useful feature of the internet connection wizard. For my part I did not change any email settings so didn't think to check them. I will in future

Geek episodeover. One positive is that I have been able to work at full capacity again. so hopefully the worst of this virus is over. Yay! Thanks for your prayers.

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