These days many mailservers are requiring reverse DNS (rDNS) and SPF records to validate the sender from this domain.

How does SPF work:

SPF is easy to understand. The “Internet” uses DNS (Domain Name System) to resolve Domain Names (as an example www.msexchange.org) into IP addresses. DNS is also used to direct requests for different services like e-mail and Web Servers. For every Domain around the world an MX (Mail Exchanger) record must exist. An MX record tells the e-mail sender where the target server for receiving mail is located.

SPF is publishing “reverse MX” records in DNS which tells the mail sender which machines send mail from the domain.

The recipient of the e-mail can now check these records to ensure that e-mail is coming from a “trusted” sender from this domain.

These “reverse MX” records can be easily published in DNS. It takes only one line in DNS to fullfil all requirements.

Microsoft has come up with a good and easy wizard (webpage not downloadable tool) that asks a few questions and spits out the correct SPF.

How to add SPF file to Windows Server DNS - link

OpenSPF Website - link or old site

The following procedure can be used on a Snap Server (tested with 2200) to reset the settings to factory defaults:

1. Power off the Snap Server (wait for all lights to turn off).
2. Hold down the reset button while powering the Snap Server on.  Wait for the System and Disk lights to flash in unison.
3. Release the reset button.
4. Press the reset button again according to the action you wish to perform:
   • Once to reset the IP address.
   • Twice to reset the Admin password (default is blank).
   • Three times to clear the network settings
   • Four times to clear all settings
   • Five times to initiate FLUP mode (for updates)
   • Six times to boot without mounting hard drives.
5. Watch the disk light to confirm that it blinks the correct number of times to correspond with your selection.  If it doesnt, repeat step 4.
6. Press and hold the reset button until the Snap Server resets.

http://technet2.microsoft.com/windowsserver/en/library/8fa42e83-ec08-4a9b-9057-8909f7ed433e1033.mspx?mfr=true
This command-line tool displays the DHCP servers active on the subnet. If it detects any unauthorized DHCP servers, it beeps and sends out alert messages. It also displays packets that it detects from DHCP servers; you can specify whether to display packets from all DHCP servers or only those from unauthorized servers.

You can also use this tool to determine which DHCP servers are available to a DHCP client and to detect unauthorized DHCP servers on a subnet.

Here is the DHCPLOC syntax:

dhcploc /p /a:”AlertNameList” /i:AlertInterval ComputerIPAddress [ValidDHCPServerList]

/p suppresses display of detected packets from any of the authorized DHCP servers specified in ValidDHCPServerList. /a:”AlertNameList” sends alert messages to the names in AlertNameList if any unauthorized DHCP servers are found.

/i:AlertInterval specifies the alert frequency in seconds.

ComputerIPAddress specifies the IP address of the computer from which you are running DHCPLoc. If the computer has multiple adapters, you must specify the IP address of the adapter that is connected to the subnet you want to test.

ValidDHCPServerList specifies the IP addresses of any number of authorized DHCP servers. The tool does not send alerts when it detects packets from the servers in this list; however, it displays those packets unless you use the /p parameter.

Kazmarek Employees can find the utility on the KTS FTP server in the \Downloads\Microsoft Windows - Server\DHCPLoc\ location

Alternativily the utilty is available in the Support Tools directory on the Windows Server CD.

Netgear wireless routers can be used as an AP using the following supported method from Netgear:

http://kbserver.netgear.com/kb_web_files/n101496.asp

http://www.phenoelit.de/dpl/dpl.html