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I found the solution myself: &nbsp;The unencrypted, non-SSL POP3-port needed to be opened between the front-end and the back-end-server.
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I found the solution myself:  The unencrypted, non-SSL POP3-port needed to be opened between the front-end and the back-end-server.

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I have set up a &nbsp;Exch2003-front-end-server sitting in the DMZ. &nbsp;It provides Outlook Web Access for employees outside in the internet. The mailboxes are sitting on a different server, inside our firewall protected intranet. With Outlook Web Access this works fine.<br />
But when I try to get access to the mailboxes through POP3, I cannot log into the front-end-server. This doesn't even work from the Outlook Express installed on that Exch2003-front-end-server &nbsp;itself. <br />
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When I connect with &quot;telnet 127.0.0.1 110&quot;, the server is responding with its name and &quot;+OK&quot;. Then I can send my user -name, but after sending the password I get a &quot;-ERR Connect attempt failed. &nbsp;Server may be down or too busy to respond.&quot;<br />
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Any ideas?<br />

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I have set up a  Exch2003-front-end-server sitting in the DMZ.  It provides Outlook Web Access for employees outside in the internet. The mailboxes are sitting on a different server, inside our firewall protected intranet. With Outlook Web Access this works fine.
But when I try to get access to the mailboxes through POP3, I cannot log into the front-end-server. This doesn't even work from the Outlook Express installed on that Exch2003-front-end-server  itself. 

When I connect with "telnet 127.0.0.1 110", the server is responding with its name and "+OK". Then I can send my user -name, but after sending the password I get a "-ERR Connect attempt failed.  Server may be down or too busy to respond."

Any ideas?


POP3-Login into Front-End-Server fails. OWA works fine.

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.