SMTP Not Available Outside Network

Posted on 2010-08-19
Last Modified: 2012-08-14
I am trying to set up IMAP access for my mobile users. I have opened the appropriate ports in the firewall (993,25) and, as far as i know, configured the SMTP connector, and the SMTP virtual server correctly.

I can set up IMAP and SMTP inside the network, and it works fine. I can telnet to the aforementioned ports, and they respond as they should. The problem is, when I try to set up an email client from outside the network, the SMTP service does not connect the the network. Furthermore, I cannot telnet to port 25. I can connect to the IMAP port, but not the SMTP port. When i telnet to port 25, all i get is a blank screen with a blinking prompt.

Any help would be greatly appreciated.
Question by:dcts
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Expert Comment

by:Casey Herman
ID: 33478527
you have to set the allowed ip's in the SMTP connector if this is exchange which it sounds that way.

Author Comment

ID: 33478709
I assume you mean the Relay Restrictions under the Access tab of the default SMTP virtual server properties? If so, I have the Ip address of my spam filter in there, and the checkbox that allows all authenticated computers to relay regardless of the list. I still cannot get access to port 25.

Expert Comment

ID: 33485155
Are you sure you want to do this anyway?  You run the risk of becoming an open relay if you are going to allow anyone from an external IP address to use your SMTP server.

Regardless, double check all of the settings on the SMTP virtual server to make sure something else isn't prohibiting the connection.  Particularly, under Authentication, make sure you have "Anonymous" checked and under Connections, make sure you have "All except the list below" checked.  If you changed anything, restart the SMTP server to enable the changes.
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LVL 10

Expert Comment

by:Casey Herman
ID: 33485213
Can you telnet to itself from the server IE
telnet localhost 25 or or the servers ip?
make sure authentication is set to anonymous like Crimmel said.
Make it wide open (Grant All) then add your spam filter ip's in after to lock it down to that and your local subnet or just what you need on your subnet.  IE scan to email devices.   I


Author Comment

ID: 33485602
I can telnet to localhost 25 on the SMTP server. The only reason I need smtp/imap is becuase a few users need to set up mobile access from their non-exchange capable phones. If there is a different way to do this besides enabling SMTP, i am open to suggestions.

Otherwise, I have the authentication settings checked for anonymous, basic auth, and integrated windows auth. Under connection, I have the checkbox "all except..." checked, with no computers in the list.

In Relay Restrictions, I have "Only the list below" checked with my spam filter's IP in the box. I still cant seem to get a connection from Outlook on my test client located outside the network. I can connect to IMAP fine, but SMTP cant connect.
LVL 10

Expert Comment

by:Casey Herman
ID: 33485853
You should be able to call the phone providers and have them authenticate to their phone ISP for outgoing mail.
What brands / carriers are the phones?

LVL 10

Accepted Solution

Casey Herman earned 500 total points
ID: 33485863
Make sure and remeber to lock those ip's back down to your spam filter or spam will get past it.

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