Outlook is unable to connect to the proxy server. (Error Code 0) RPC/HTTP

[Mike Bonvie]

We have just commissioned 2 new Exchange 2007 farms in our domain.

EXC7 which is a Mailbox Role in SCR configuration

EXC6 with is 2 nodes of UM, CAS, HUB behind F5 Balancer

we also have an original exchange 2003 pair of clusters

Internally on the LAN Outlook users have no issues logging to their mailbox
and working;

however on the WAN with NO VPN, outlook users with RPC/HTTP configured have
issues accessing mailbox hosted on the new EXC7 servers.

These users are prompted in a windows Dialogue for User Name and Password,
which in the logs of the server appears to be passed ok, however the user is
constantly prompted and does not actually get in. The user also receives an
error message:

Microsoft Office Outlook

There is a problem with the proxy server's security certificate. The name on
the security certificate is invalid or does not match the name of the target
site mail2007.domainx.com.

Outlook is unable to connect to the proxy server. (Error Code 0)

Any ideas would be greatly appreciated

Thanks!
Mike Bonvie

[Jan-Philipp Wagner]

Mike Bonvie schrieb:

Hi,

is this an official certificate you are using? Otherwise you may have to
import it to the local certificate store of the client.

Philipp