Migrating application mailboxes to Exchange Online is critical for any migration project, and thorough planning is required since application mailboxes often serve vital business functions. It’s imperative to gather the details outlined in this article prior to updating internal application code, or test feature functionality of third-party products.
Why I recommend you don't leave POP and IMAP protocol logging enabled on Exchange Servers.
This tutorial demonstrates how to configure ISA Server 2006 to allow Exchange 2010 mailbox access by remote email clients.
How to configure the Exchange Server 2010 POP3 client settings in Windows Live Mail, a free email client from Microsoft.
How to publish Exchange 2010 POP3 and SMTP server settings so that end users know how to configure their email client.
This Exchange Server 2010 tutorial demonstrates how to enable or disable POP3 access for mailbox users and manage POP3 settings for multiple mailboxes at once.
How to configure the Exchange 2010 POP3 service to allow remote email users to connect securely without exposing their user credentials to attackers.
Exchange Server 2010 includes support for POP3 remote access to email, but will require some initial setup and configuration before you can use it.