Exchange 2007 Sender Policy Framework
Hi. We are looking at increasing our security and one of the tasks is to deny hackers that TELNET to our mail server via port 25 and send an email from a user thats on my domain to another user thats on my domain. If an hacker does this the originating IP will be external thus this must not be allowed. However, I tried changing some settings in Exchange 2007 under Receive connectors but then my emails start queing up so i had to reverse my changes. Please advise. I dont want to change port 25 nor do I want to deny telnet, i believe its IPs allowed in receive connectors that i have to change but how.Thanks
Rajith Enchiparambil
If you are so concerned, why don't you disable telnet acces on your firewall and open it only when you need to test something?
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ASKER
Hi qupnit. Let me give you an example. User A on my networks email address is userA@domain.com and User B on my network is userB@domain.com. If a hacker telnets to my exchange server on port 25 and then sends an email from userA@domain.com to userB@domain.com requesting him to transfer money urgently to a bank account. userB will not know its a hacker and will then transfer the money which is a huge security risk. We cant blcok userA email address because its valid but surely there is a way to block an email address if its an internal email address but is not from an internal Ip address
ASKER
HI All. Thanks but i found the solution. We basically added the Anti Spam Ip's to our firewall whereby we allowing only mails from these IP's over port 25. Now if i telnet from the outside to my exchange server it denies access. PERFECT....thanks
Great
Cheers
Nitin
Cheers
Nitin