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Users unable to send mail via IMAP/POP3 set ups (Exchange 2003)

I have a client who has a Exchange 2003 environment. Email flows in and out just fine internally. Problem is that no one is able to send mail externally using mail.mycompany.com. SMTP outbound security is set for Anonymous Access. I have tried setting the Outgoing Server settings on the client side to use the same login as the incoming access but that does not work. I am sure this is easy to fix but I am at a loss at what to change to resolve the issue. Incoming mail works just fine externally.

Alginald

Looks like the server is not set to allow relaying from the clients...

There are various ways of doing this, either anonymous relaying, or authenticated relaying...

Navigate in the Exchange System Manager to the Default SMTP Virtual Server, and go to the access tab. Now either:-
1) Click on relay restrictions and select "Only the list below" and add your internal IP subnet (e.g. 192.168.0.0/24)
2) Alternatively, on the same tab, make sure that "Allow all computers wich successfully authenticate" is set, and then on the Access Control tab enable basic authentication or Integrated Windows (depends on the clients). Finally, make sure the clients are configured to use same credentials for outgoing server

endital1097

i would test a telnet session into your exchange server over port 25
telnet yourserver.domain.com 25

there are many isps that are currently blocking port 25 outbound

greywind

ASKER

Thanks guys. I look into these suggestions when I get into the office later today.

greywind

ASKER

endital1097 - Port 25 is open. Internal email sends just fine via port 25. Thanks.

greywind

ASKER

Alginald - I checked all the settings and they are all set to what you recommend. Any other ideas?

Thanks

endital1097

try a complete telnet session

telnet server.domain.com 25
ehlo yourdomain.com
mail from: you@yourdomain.com
rcpt to: someone@gmail.com
data
subject: test message
this is a test
.

greywind

ASKER

Telnet was successful. If I VPN into the network outgoing email works just fine.

endital1097

the telnet test was successful from an external connection

greywind

ASKER

Actually no. If I do it externally it says connection failed.

endital1097

i would also attempt to connect to another smtp server from the external connection
telnet mx1.hotmail.com 25

if that fails, then the issue is with your isp

endital1097

look for your isp here
http://www.amailsender.com/support/smtpserver/

greywind

ASKER

We use a (isp SMTP) Smart Host to route mail. I am able to externally telnet to that isp SMTP just fine.

greywind

ASKER

I am using mail.mydomain.com for the smtp address in outlook. I am not sure why I can't connect to that externally via port 25. Incoming mail comes in via port 25 so it shouldn't be blocked at the firewall.

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endital1097

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greywind

ASKER

This is the case with all users around the country.

greywind

ASKER

So you are saying that some isp will block you from using all other smtp addresses but their own?