Proxy session setup failed on Frontend with '441

[nochance]

Email User gets this response:

Diagnostic information for administrators:
Generating server: DBXPR04MB031.eurprd04.prod.outlook. com
Receiving server: emea01-internal.map.protection.outlook. com (10.47.216.25)

user@ourdomain. com

11/10/2013 1:31:03 AM - Remote Server at emea01-internal.map.protection.outlook. com (10.47.216.25) returned '550 4.4.7 QUEUE.Expired; message expired'
11/10/2013 1:22:20 AM - Remote Server at emea01-internal.map.protection.outlook. com (10.47.216.25) returned '450 4.7.0 Proxy session setup failed on Frontend with '441 4.4.1 Error encountered while communicating with primary target IP address: "Failed to connect. Winsock error code: 10060, Win32 error code: 10060." Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was xxx.214.xxx.125:25''

xxx's added.

MS SAYS THIS:
http://support.microsoft. com/kb/979175

basically saying it's a firewall issue, so if that's true please can I have a clue what to look at and how to fix it? I am at a loss where to start, being a beginner.

The ip addresses in the headers are not in csf.deny.

edit: I am not running exchange server, I have a unix vps system with cpanel.

If not...

thanks :-)

[nochance]

I found this:

http://forums.cpanel. net/f43/t-remote_smtp-defer-53-retry-time-not-reached-any-host-72383.html

delete space I have put in cpanel. net to enable the link

also found this:

You many need to recreate the exim DB.

remove the content of /var/spool/exim/db/ after stopping exim


Now, start the exim server.

I also suspect dkim, which I have now I think disabled at dkim_disable :
http://www.exim. org/exim-html-current/doc/html/spec_html/ch-support_for_dkim_domainkeys_identified_mail.html

delete the space before .org to enable the link