Hi, We are thinking about security of the email services at our network, we have exchange 2000 servers, smtp gateways on unix and 3 firewall's The goal is to rise the security level of our internal email process, such as user authentication and content checking of all email send. At first we were thinking about PKI, but I've spoken with some colleges and a engineer for Microsoft technical support, and implementing PKI seems to be a real challenge/impossible. According to Microsoft pki is not working properly on windows 2000, maybe on windows 2003, but they are not for sure if that's true. I would like to know if anyone has past experience with pki or other authentication methods... The basic thing we want to accomplish is that each email send is really from the official owner of the email address, so it has to be some kind of user authentication and not session authentication, and it has to work on different platforms (microsoft/novell/unix), and different user input devices (workstation,pda,thinclient,wireless lan). For the content checking I was thinking towards GFI software, Mail essentials, security. I would like to hear your experience especially with pki Thanks Martijn Spelt SR. System Engineer Technology Solutions Microsoft Inter Access B.V. Creating Value in the EUR-conomy Marathon 5 1213 PC Hilversum Postbus 840 1200 AV Hilversum Telefoon +31 (0)35 688.84.00 Fax +31 (0)35 688.85.52 GSM +31 (0)6 21218792 E-mail Martijn.spelt@xxxxxxxxxxxxxx Bezoek <http://www.interaccess.nl/>. Dat is de moeite waard!