MS: Exchange 2007 POP3 Client Access Configuration

1. Set MSExchangePOP3 service to automatic
Set-service msExchangePOP3 -startuptype automatic

2.Configure IP Address and Port for POP3

a.To set the IP address and port for communicating with Exchange using POP3 with SSL, run the following command:
Set-PopSettings -SSLBindings: IPaddress:Port

b.To set the IP address and port for communicating with Exchange using POP3 with no encryption or Transport Layer Security (TLS) encryption:
Set-PopSettings -UnencryptedOrTLSBindings IPaddress:Port

3.Configure POP3 Authentication - POP3 (110) /POP3 SSL (995)

a.If you will not be using TLS encryption and you want to allow Basic authentication on an unsecured port, run the following command:
Set-PopSettings -LoginType PlainTextLogin

b.If you will not be using TLS, but you want to restrict Basic authentication to use only secured ports, run the following command:
Set-PopSettings -LoginType PlainTextAuthentication

c.If you want to use TLS encryption before authentication, run the following command:
Set-PoPSettings -LoginType SecureLogin

4.Enable POP3 Protocol for the User Mailbox (Enabled by default)
Set-CasMailbox MailboxName -Popenabled:$true ($false disables the protocol for the specified user)

5.Configure the SMTP Receive Connector on the Exchange Server to Allow Anonymous in order to send Email using the following command:
Set-ReceiveConnector "Servername\default Servername" -PermissionGroups “ExchangeServers,ExchangeUsers,ExchangeLegacyServers,AnonymousUsers"

6.Restart the Microsoft Exchange POP3 Service
Restart-service MSExchangepop3

7. Check the status of the Microsoft Exchange POP3 Service
Get-Service MSExchangepop3

8.Dump the POP3 configuration
Get-PopSettings

Note: Remember do not use the Administrator account to test POP3, IMAP, SMTP.