The “Account Information” page of the Exchange Control Panel (ECP) contains a pointer to “Settings for POP, IMAP, and SMTP access…” The intention is to provide users with the information that they need to input into clients that use these protocols so that they can connect to Exchange. Users need to know the name of the client access server to which to connect, the port number for the protocol, and the encryption type security setting. These values are held in the ExternalConnectionSettings property of the CAS server and are set using the Set-POPSettings and Set-IMAPSettings cmdlets.

Unfortunately, if you leave the default settings in place, users will see blank values when they access the page. To provide the information, you have to take three steps:

• Provide details for POP3 access:

Set-POPSettings –ExternalConnectionSettings ExServer2.contoso.com:995:SSL -Server ExServer2

• Provide details for IMAP4 access:

Set-IMAPSettings –ExternalConnectionSettings ExServer2.contoso.com:993:SSL –Server ExServer2

• Most companies provide a receive connector on a hub transport server that POP3 and IMAP4 clients can use to relay their outgoing messages. To make users aware of which server to use, you publish information about the connector by setting its AdvertiseClientSetting property to $True. In this case, I’m telling users to connect to the default receive connector on a hub transport server, but in production circumstances you’d be more likely to create a specific receive connector that is dedicated and configured to act as a client relay.

Set-ReceiveConnector –Identity ‘ExServer2\Default ExServer2’ –AdvertiseClientSettings $True

Remember that the POP3 and IMAP4 settings are server-specific, so you have to set the values on all the CAS servers that you want to use for this purpose.

A restart of IIS on the CAS server may be necessary to make the new values available to clients. Afterwards, users should be able to see values for connection settings as shown below:

How ECP displays connection protocol settings to users

Hope this helps to fill in one of the mysteries thrown up by Exchange 2010.

– Tony

Read more about the Exchange Control Panel and how to use it effectively in my Microsoft Exchange Server 2010 Inside Out book!