Determining Authentication Levels

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1

There are four binding types that determine the level of authentication used for connections. The option selected affects other options.

Binding type	Description
Anonymous	No authentication is required. Select this option when the server does not require account and password information.
Plaintext	This option allows the transmission of account information and passwords in plaintext. When this option is selected, account and password information is required.
Windows SSPI	The client and server negotiate to determine which level of authentication is acceptable by both, and use the strongest method available. When this option is selected, account and password information is required.
Service accounts	Uses the account information of the user under which the SMTP service is running. This is controlled by Component Services, under Administrative Tools.