大易网志
[上文摘译自Windows XP: The Official Magazine July 2005, wooway尊重原有的版权, 如有异议, 请联络wooway.]
没用的特性 – 数字变焦
NOT ALL ZOOM is created equal. While optical zoom uses the camera’s lens to increase magnification, digital zoom uses software built into a camera to magnify a subset of an image captured by a lens. The software does this by upsampling (or interpolating) pixels—generating new image data based on samples from the original pixels. That process can degrade the quality of the photo, making it blurry and pixelated. Optical zoom is the important number to look for. —Grace Aquino
一些DC厂商的广告里 (图示为日本品牌:奥林巴斯) 会给出光学和数字变焦的综合值来蒙骗顾客.
How to log on to Windows XP if you forget your password or your password expires
You can use the IIS SMTP mail relay service to prevent spammers from directly interacting with your Microsoft Exchange Server!
Your Exchange Server is probably set up on your internal network to receive all mail for users in your domain for onward delivery. If you publish your Exchange Server’s SMTP service, Internet users can send messages directly to your Exchange Server. Allowing the Internet to have direct contact with your Exchange Server is never a good idea. To stop this direct contact, set up an IIS SMTP relay, and instead of publishing the Exchange Server’s SMTP service, publish the IIS SMTP Service. Now when mail destined for yourdomain.com hits the external interface of your firewall, it will be forwarded to the SMTP relay. The SMTP relay in turn forwards it to your Exchange Server. Now set your Exchange Server to send outgoing SMTP mail messages to the IIS SMTP relay server so it forwards them on to the Internet.
To secure this set up, for incoming mail, allow the IIS SMTP server to relay only to your own domains. For outgoing mail, allow the IIS SMTP server to relay to all domains. If you allow incoming mail to be relayed to all domains, spammers will take advantage of your open mail relay and you’ll process thousands of spam e-mails within a few days. A default configuration allows all computers that can authenticate to relay through the server; however, authentication requires more overhead, so it’s better to allow relay based on IP address. Since you only want to allow your Exchange Server to use the IIS SMTP Server as an open relay, add the IP address of your Exchange Server to Allow "Only the list below." You need to allow the IIS SMTP Service to act as an open relay for your Exchange Server because the Exchange Server needs to send SMTP mail to all Internet mail domains. The open relay for outbound mail is required. You also need to prevent relay for incoming messages. Do this by configuring the server to relay only messages destined to your own domain:
Another advantage of this set up is that you can take down the Exchange Server for maintenance without losing any incoming mail. You can also improve fault tolerance by setting up multiple IIS SMTP Servers. Another possibility would be to add an additional mail relay server to filter e-mail for spam or viruses before relaying it on to the Exchange Server.
by Michael Cobb
01 Jun 2005 | SearchSecurity.com