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ryanj1987

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Can't telnet SMTP Server outside of firewall

I'm not able to access my smtp server outside of the network. Initially my thought was firewall... But I double and triple checked; as well as had two others verify that port 25 IS being forwarded to the Exchange box. I'm able to telnet into it inside the network, or using VPN without any problem.

It's running Exchange 2003 SP2 on Windows Server 2003 firewalled by a SonicWALL TZ-170 with content filtering and IPS. No logs can be found on the firewall in reference to port 25.
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maxis2cute

can you explain what type  of access your are talking about?    are you trying to gain accress from the outside to the exchange box? is mail not being fowarded? i could use a little more information
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It's the stragest thing ... The exchange server is able to send / receive mail from users inside the network, but when i try to telnet into the server on port 25 (SMTP) it doesn't connect; so trying to setup POP3 in Outlook fails to send (Because it can't connect to exchange).
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maxis2cute

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Ah okay, found the problem. The firewall was dropping the TCP connection because the IP Address for the hotel is blacklisted as spam, as you can see below it wasn't getting marked as an attack or abnormal behavior ... and wasn't even being logged until I turned it on. Once i'm out of the hotel, and under a non-blacklisted IP, it should work fine.

Sonicwall Log:

Notice -  Network Access - TCP connection dropped - xxx.xxx.xxx.xxx, 35215, WAN (admin) ExchIP, 25, LAN - TCP - SMTP (Send E-Mail)  
Notice - RBL Inbound - connection from RBL-listed SMTP server dropped - xxx.xxx.xxx.xxx, 35215, WAN (admin) ExchIP, 25, LAN
excellent.